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                                                                     EXHIBIT 4.8

                                                                  EXECUTION COPY

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                           IRON MOUNTAIN INCORPORATED

                           THE GUARANTORS NAMED HEREIN

                                       AND

                              THE BANK OF NEW YORK,
                                   as Trustee

                    7 3/4% Senior Subordinated Notes due 2015

                          FIRST SUPPLEMENTAL INDENTURE

                          Dated as of December 30, 2002

                                       TO

                           SUBORDINATED DEBT INDENTURE

                          Dated as of December 30, 2002

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                                TABLE OF CONTENTS

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ARTICLE 1. DEFINITIONS............................................................................................1

   Section 1.1.    DEFINITIONS....................................................................................1

ARTICLE 2. FORM AND TERMS OF THE NOTES...........................................................................15

   Section 2.1.    FORM AND DATING...............................................................................15
   Section 2.2.    EXECUTION AND AUTHENTICATION..................................................................16
   Section 2.3.    DEPOSITORY AND PAYING AGENT FOR NOTES.........................................................17
   Section 2.4.    TRANSFER AND EXCHANGE OF NOTES................................................................17
   Section 2.5.    REDEMPTION....................................................................................19
   Section 2.6.    COVENANTS.....................................................................................21
      (a)     Restricted Payments................................................................................21
      (b)     Incurrence of Indebtedness and Issuance of Preferred Stock.........................................24
      (c)     Liens..............................................................................................25
      (d)     Dividend and Other Payment Restrictions Affecting Restricted Subsidiaries..........................25
      (e)     Transactions with Affiliates.......................................................................27
      (f)     Certain Senior Subordinated Debt...................................................................28
      (g)     Additional Subsidiary Guarantees...................................................................28
      (h)     Designation of Unrestricted Subsidiaries...........................................................29
      (i)     Limitation on Sale and Leaseback Transactions......................................................30
      (j)     Asset Sales........................................................................................30
      (k)     Change of Control Offer............................................................................32
   Section 2.7.    SUBSIDIARY GUARANTEES.........................................................................34
   Section 2.8.    LEGAL DEFEASANCE AND COVENANT DEFEASANCE......................................................34
   Section 2.9.    SUBORDINATION.................................................................................34

ARTICLE 3. MISCELLANEOUS.........................................................................................34

   Section 3.1.    EFFECT OF HEADINGS............................................................................34
   Section 3.2.    SUCCESSORS AND ASSIGNS........................................................................34
   Section 3.3.    SEPARABILITY CLAUSE...........................................................................34
   Section 3.4.    GOVERNING LAW.................................................................................34
   Section 3.5.    FIRST SUPPLEMENT TO SUPERSEDE INDENTURE.......................................................34
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EXHIBITS

Exhibit A         FORM OF NOTES
Exhibit B         FORM OF SUPPLEMENTAL INDENTURE

                                        i
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               THIS FIRST SUPPLEMENTAL INDENTURE, dated as of December 30, 2002
("FIRST SUPPLEMENTAL INDENTURE"), is by and between IRON MOUNTAIN INCORPORATED,
a Pennsylvania corporation (the "COMPANY"), having its principal office at 745
Atlantic Avenue, Boston, Massachusetts 02111, the Guarantors signatory hereto,
and THE BANK OF NEW YORK, a New York banking corporation, as trustee (the
"TRUSTEE"), having its principal corporate trust office at 101 Barclay Street, 8
Floor West, New York, NY 10286.

                                   WITNESSETH:

               WHEREAS, the Company and The Bank of New York, acting as trustee,
executed and delivered a Subordinated Indenture, dated as of December 30, 2002
(the "INDENTURE"), to provide for the issuance by the Company from time to time
of Securities to be issued in one or more series as provided in the Indenture;

               WHEREAS, the issuance and sale of up to $160,000,000, aggregate
principal amount of a series of the Company's Securities (the "NOTES") have been
authorized by resolutions adopted by the Board of Directors of the Company on
November 27, 2002;

               WHEREAS, the Company desires to issue and sell $100,000,000
aggregate principal amount of the Notes on the date hereof;

               WHEREAS, the Company desires to enter into this First
Supplemental Indenture pursuant to Section 9.1(e) of the Indenture to supplement
the Indenture to establish the form and terms of the Notes; and

               NOW, THEREFORE, for and in consideration of the premises stated
herein and the purchase of the Notes by the Holders thereof, the parties hereto
hereby enter into this First Supplemental Indenture, for the equal and
proportionate benefit of all Holders of Notes, as follows:

                                   ARTICLE 1.

                                   DEFINITIONS

Section 1.1. DEFINITIONS.


               (a)  All of the terms used in this First Supplemental Indenture
which are defined in the Indenture shall have the meanings specified in the
Indenture, unless otherwise defined herein (in which case they shall have the
meanings defined herein for the purposes of the Indenture as well as for the
First Supplemental Indenture) or unless the context otherwise requires, and for
the purposes of this First Supplemental Indenture, the following terms have the
meanings set forth in this Section:

               "ACQUIRED DEBT" means, with respect to any specified Person:

               (1)  Indebtedness of any other Person, existing at the time such
                    other Person merged with or into or became a Subsidiary of
                    such specified Person, including Indebtedness incurred in
                    connection with, or in contemplation of, such other Person
                    merging with or into or becoming a Subsidiary of such
                    specified Person; and

               (2)  Indebtedness encumbering any asset acquired by such
                    specified Person.

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               "ACQUISITION EBITDA" means, as of any date of determination, with
respect to an Acquisition EBITDA Entity, the sum of:

               (1)  EBITDA of such Acquisition EBITDA Entity for its last fiscal
                    quarter for which financial statements are available at such
                    date of determination (adjusted to give pro forma effect to
                    any acquisition or disposition of a business or Person by
                    such Acquisition EBITDA Entity consummated during the period
                    covered by, or after the date of, such quarterly financial
                    statements), multiplied by four (or if such quarterly
                    statements are not available, EBITDA for the most recent
                    fiscal year for which financial statements are available),
                    plus

               (2)  projected quantifiable improvements in operating results (on
                    an annualized basis) due to cost reductions calculated in
                    good faith by the Company or one of its Restricted
                    Subsidiaries, as certified by an Officers' Certificate filed
                    with the Trustee, without giving effect to any operating
                    losses of the acquired Person.

               "ACQUISITION EBITDA ENTITY" means, as of any date of
determination, a business or Person:

               (1)  which has been acquired by the Company or one of its
                    Restricted Subsidiaries and with respect to which financial
                    results on a consolidated basis with the Company have not
                    been made available for an entire fiscal quarter; or

               (2)  which is to be acquired in whole or in part with
                    Indebtedness, the incurrence of which will require the
                    calculation on such date of the Acquisition EBITDA of such
                    Acquisition EBITDA Entity for purposes of Section 2.6(b) of
                    this First Supplemental Indenture (Section 4.9 of the
                    Indenture).

               "ADDITIONAL NOTES" means such amount of the Company's 7 3/4%
Senior Subordinated Notes due 2015 (other than the Initial Notes) as the Company
may issue from time to time under this First Supplemental Indenture in
accordance with Section 2.2 hereof as part of the same series as the Initial
Notes.

               "ADJUSTED EBITDA" means, as of any date of determination and
without duplication, the sum of:

               (1)  EBITDA of the Company and its Restricted Subsidiaries for
                    the most recent fiscal quarter for which internal financial
                    statements are available at such date of determination,
                    multiplied by four; and

               (2)  Acquisition EBITDA of each business or Person that is an
                    Acquisition EBITDA Entity as of such date of determination,
                    multiplied by a fraction, (i) the numerator of which is
                    three minus the number of months (and/or any portion
                    thereof) in such most recent fiscal quarter for which the
                    financial results of such Acquisition EBITDA Entity are
                    included in the EBITDA of the Company and its Restricted
                    Subsidiaries under clause (1) above, and (ii) the
                    denominator of which is three. The effects of unusual items,
                    including merger-related expenses permitted to be shown as a
                    separate line item on a statement of operations in
                    accordance with GAAP, or non-recurring items in respect of
                    the Company, a Restricted

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                    Subsidiary or an Acquisition EBITDA Entity occurring in any
                    period shall be excluded in the calculation of Adjusted
                    EBITDA.

               "AGENT MEMBERS" means members of, or participants in, the
Depository.

               "ATTRIBUTABLE INDEBTEDNESS" in respect of a Sale and Leaseback
Transaction means, as of the time of determination, the greater of:

               (1)  the fair market value of the property subject to such
                    arrangement (as determined by the Board of Directors of the
                    Company) and

               (2)  the present value (discounted at the rate of interest
                    implicit in such transaction) of the total obligations of
                    the lessee for rental payments during the remaining terms of
                    the lease included in such Sale and Leaseback Transaction
                    (including any period for which such lease has been
                    extended).

               "CANADA COMPANY" means Iron Mountain Canada Corporation, a Wholly
Owned Subsidiary of the Company, formerly known as Pierce Leahy Canada Company.

               "CASH EQUIVALENTS" means:

               (1)  securities with maturities of one year or less from the date
                    of acquisition, issued, fully guaranteed or insured by the
                    United States Government or any agency thereof;

               (2)  certificates of deposit, time deposits, overnight bank
                    deposits, bankers acceptances and repurchase agreements
                    issued by a Qualified Issuer having maturities of 270 days
                    or less from the date of acquisition;

               (3)  commercial paper of an issuer rated at least A-2 by Standard
                    & Poor's Rating Group, a division of McGraw Hill, Inc., or
                    P-2 by Moody's Investors Service, or carrying an equivalent
                    rating by a nationally recognized rating agency if both of
                    the two named rating agencies cease publishing ratings of
                    investments and having maturities of 270 days or less from
                    the date of acquisition;

               (4)  money market accounts or funds with or issued by Qualified
                    Issuers; and

               (5)  Investments in money market funds substantially all of the
                    assets of which are comprised of securities and other
                    obligations of the types described in clauses (1) through
                    (3) above.

               "CHANGE OF CONTROL" means the occurrence of any of the following
events:

               (1)  any "person" or "group" (as such terms are used in Sections
                    13(d) and 14(d) of the Exchange Act), other than the
                    Principal Stockholders (or any of them), is or becomes the
                    "beneficial owner" (as defined in Rules 13d-3 and 13d-5
                    under the Exchange Act), directly or indirectly, of more
                    than a majority of the voting power of all classes of Voting
                    Stock of the Company;

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               (2)  the Company consolidates with, or merges with or into,
                    another Person or conveys, transfers, leases or otherwise
                    disposes of all or substantially all of its assets to any
                    Person, or any Person consolidates with, or merges with or
                    into, the Company, in any such event pursuant to a
                    transaction in which the outstanding Voting Stock of the
                    Company is converted into or exchanged for cash, securities
                    or other property, other than any such transaction where (i)
                    the outstanding Voting Stock of the Company is not converted
                    or exchanged at all (except to the extent necessary to
                    reflect a change in the jurisdiction of incorporation) or is
                    converted into or exchanged for (A) Voting Stock (other than
                    Disqualified Stock) of the surviving or transferee Person or
                    (B) cash, securities and other property (other than Capital
                    Stock described in the foregoing clause (A)) of the
                    surviving or transferee Person in an amount that could be
                    paid as a Restricted Payment pursuant to Section 2.6(a) of
                    the First Supplemental Indenture (Section 4.8 of the
                    Indenture) and (ii) immediately after such transaction, no
                    "person" or "group" (as such terms are used in Sections
                    13(d) and 14(d) of the Exchange Act), other than the
                    Principal Stockholders (or any of them), is the "beneficial
                    owner" (as defined in Rules 13d-3 and 13d-5 under the
                    Exchange Act), directly or indirectly, of more than a
                    majority of the total outstanding Voting Stock of the
                    surviving or transferee Person;

               (3)  during any consecutive two-year period, individuals who at
                    the beginning of such period constituted the Board of
                    Directors (together with any new directors whose election to
                    such Board of Directors, or whose nomination for election by
                    the stockholders of the Company, was approved by a vote of
                    66 2/3% of the directors then still in office who were
                    either directors at the beginning of such period or whose
                    election or nomination for election was previously so
                    approved) cease for any reason to constitute a majority of
                    the Board of Directors then in office; or

               (4)  the Company is liquidated or dissolved or adopts a plan of
                    liquidation or dissolution other than in a transaction which
                    complies with Section 5.1 of the Indenture.

               "CONSOLIDATED ADJUSTED NET INCOME" means, for any period, the net
income (or net loss) of the Company and its Restricted Subsidiaries for such
period as determined on a consolidated basis in accordance with GAAP, adjusted
to the extent included in calculating such net income or loss by excluding:

               (1)  any net after-tax extraordinary gains or losses (less all
                    fees and expenses relating thereto);

               (2)  any net after-tax gains or losses (less all fees and
                    expenses relating thereto) attributable to Asset Sales;

               (3)  the portion of net income (or loss) of any Person (other
                    than the Company or a Restricted Subsidiary), including
                    Unrestricted Subsidiaries, in which the Company or any
                    Restricted Subsidiary has an ownership interest, except to
                    the extent of the amount of dividends or other distributions
                    actually paid to the Company or any Restricted Subsidiary in
                    cash dividends or distributions by such Person during such
                    period; and

                                        4
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               (4)  the net income (or loss) of any Person combined with the
                    Company or any Restricted Subsidiary on a "pooling of
                    interests" basis attributable to any period prior to the
                    date of combination.

               "CONSOLIDATED INCOME TAX EXPENSE" means, for any period, the
provision for federal, state, local and foreign income taxes of the Company and
its Restricted Subsidiaries for such period as determined on a consolidated
basis in accordance with GAAP.

               "CONSOLIDATED INTEREST EXPENSE" means, for any period, without
duplication, the sum of:

               (1)  the amount which, in conformity with GAAP, would be set
                    forth opposite the caption "interest expense" (or any like
                    caption) on a consolidated statement of operations of the
                    Company and its Restricted Subsidiaries for such period,
                    including, without limitation:

                    (i)   amortization of debt discount;

                    (ii)  the net cost of interest rate contracts (including
                          amortization of discounts);

                    (iii) the interest portion of any deferred payment
                          obligation;

                    (iv)  amortization of debt issuance costs; and

                    (v)   the interest component of Capital Lease Obligations of
                          the Company and its Restricted Subsidiaries; plus

               (2)  all interest on any Indebtedness of any other Person
                    guaranteed and paid by the Company or any of its Restricted
                    Subsidiaries;

provided, however, that Consolidated Interest Expense will not include any gain
or loss from extinguishment of debt, including write-off of debt issuance costs.

               "CONSOLIDATED NON-CASH CHARGES" means, for any period, the
aggregate depreciation, amortization and other non-cash expenses of the Company
and its Restricted Subsidiaries (including without limitation any minority
interest) reducing Consolidated Adjusted Net Income for such period, determined
on a consolidated basis in accordance with GAAP (excluding any such non-cash
charge to the extent that it requires an accrual of or reserve for cash charges
for any future period).

               "CREDIT AGENT" means JPMorgan Chase Bank, in its capacity as
administrative agent for the lenders party to the Credit Agreement, or any
successor or successors party thereto.

               "CREDIT AGREEMENT" means that certain Fifth Amended and Restated
Credit Agreement, dated as of March 15, 2002, as amended, among the Company,
Canada Company, the lenders party thereto and the Credit Agent, as amended,
restated, supplemented, modified, renewed, refunded, increased, extended,
replaced or refinanced from time to time.

               "DEFINITIVE NOTES" means Notes that are in the form of the Notes
attached hereto as Exhibit A, that do not include the information called for by
Section 2.15 of the Indenture.

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                "EBITDA" means for any period Consolidated Adjusted Net Income
for such period increased by:

               (1)  Consolidated Interest Expense for such period; plus

               (2)  Consolidated Income Tax Expense for such period; plus

               (3)  Consolidated Non-Cash Charges for such period.

               "EQUITY INTERESTS" means Capital Stock and all warrants, options
or other rights to acquire Capital Stock (but excluding any debt security that
is convertible into, or exchangeable for, Capital Stock).

               "EQUITY PROCEEDS" means:

               (1)  with respect to Equity Interests (or debt securities
                    converted into Equity Interests) issued or sold for cash
                    Dollars, the aggregate amount of such cash Dollars; and

               (2)  with respect to Equity Interests (or debt securities
                    converted into Equity Interests) issued or sold for any
                    consideration other than cash Dollars, the aggregate Market
                    Price thereof computed on the date of the issuance or sale
                    thereof.

               "EXCLUDED RESTRICTED SUBSIDIARY" means any Restricted Subsidiary
organized under the laws of a jurisdiction other than the United States (as
defined in Regulation S under the Securities Act) and that has not delivered a
Subsidiary Guarantee.

               "EXISTING INDEBTEDNESS" means Indebtedness of the Company and its
Subsidiaries (other than under the Credit Agreement) in existence on the date of
the Indenture, until such amounts are repaid.

               "GLOBAL NOTE" means a permanent global Note that contains the
paragraph referred to in Section 2.15 of the Indenture and the additional
Schedule of Exchanges of Notes to the form of the Note attached hereto as
Exhibit A, and that is deposited with and registered in the name of the
Depository.

               "INITIAL NOTES" means the first $100,000,000 aggregate principal
amount of 7 3/4% Senior Subordinated Notes due 2015 that are issued under this
First Supplemental Indenture, as amended or supplemented from time to time
pursuant to the Indenture.

               "INVESTMENTS" means, with respect to any Person, all investments
by such Person in other Persons (including Affiliates) in the forms of loans
(including Guarantees), advances or capital contributions (excluding commission,
travel and similar advances to officers and employees made in the ordinary
course of business), purchases or other acquisitions for consideration of
Indebtedness, Equity Interests or other securities and all other items that are
or would be classified as investments on a balance sheet prepared in accordance
with GAAP.

               "LEVERAGE RATIO" means, at any date, the ratio of:

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               (1)  the aggregate principal amount of Indebtedness of the
                    Company and its Restricted Subsidiaries outstanding as of
                    the most recent available quarterly or annual balance sheet,
                    to

               (2)  Adjusted EBITDA, after giving pro forma effect, without
                    duplication, to

                    (i)   the incurrence, repayment or retirement of any
                          Indebtedness by the Company or its Restricted
                          Subsidiaries since the last day of the most recent
                          full fiscal quarter of the Company;

                    (ii)  if the Leverage Ratio is being determined in
                          connection with the incurrence of Indebtedness by the
                          Company or a Restricted Subsidiary, such Indebtedness;
                          and

                    (iii) the Indebtedness to be incurred in connection with the
                          acquisition of any Acquisition EBITDA Entity.

               "LIEN" means, with respect to any asset, any mortgage, lien,
pledge, charge, security interest or encumbrance of any kind in respect of such
asset, whether or not filed, recorded or otherwise perfected under applicable
law (including any conditional sale or other title retention agreement, any
lease in the nature thereof, any option or other agreement to sell or give a
security interest in and any filing of or agreement to give any financing
statement under the Uniform Commercial Code, or equivalent statutes, of any
jurisdiction).

               "MAKE-WHOLE AMOUNT" means, with respect to any Note, an amount
equal to the excess, if any, of:

               (1)  the present value of the remaining principal, premium and
                    interest payments that would be payable with respect to such
                    Note if such Note were redeemed on January 15, 2008,
                    computed using a discount rate equal to the Treasury Rate
                    plus 75 basis points, over

               (2)  the outstanding principal amount of such Note.

               "MAKE-WHOLE AVERAGE LIFE" means, with respect to any date of
redemption of Notes, the number of years (calculated to the nearest one-twelfth)
from such redemption date to January 15, 2008.

               "MAKE-WHOLE PRICE" means, with respect to any Note, the greater
of:

               (1)  the sum of the principal amount of and Make-Whole Amount
                    with respect to such Note; and

               (2)  the redemption price of such Note on January 15, 2008.

               "MARKET PRICE" means:

               (1)  with respect to the calculation of Equity Proceeds from the
                    issuance or sale of debt securities which have been
                    converted into Equity Interests, the value received upon the
                    original issuance or sale of such converted debt securities,
                    as determined reasonably and in good faith by the Board of
                    Directors; and

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               (2)  with respect to the calculation of Equity Proceeds from the
                    issuance or sale of Equity Interests, the average of the
                    daily closing prices for such Equity Interests for the 20
                    consecutive trading days preceding the date of such
                    computation.

               The  closing price for each day shall be:

               (1)  if such Equity Interests are then listed or admitted to
                    trading on the New York Stock Exchange, the closing price on
                    the NYSE Consolidated Tape (or any successor consolidated
                    tape reporting transactions on the New York Stock Exchange)
                    or, if such composite tape shall not be in use or shall not
                    report transactions in such Equity Interests, or if such
                    Equity Interests shall be listed on a stock exchange other
                    than the New York Stock Exchange (including for this purpose
                    the Nasdaq National Market), the last reported sale price
                    regular way for such day, or in case no such reported sale
                    takes place on such day, the average of the closing bid and
                    asked prices regular way for such day, in each case on the
                    principal national securities exchange on which such Equity
                    Interests are listed or admitted to trading (which shall be
                    the national securities exchange on which the greatest
                    number of such Equity Interests have been traded during such
                    20 consecutive trading days); or

               (2)  if such Equity Interests are not listed or admitted to
                    trading on any such exchange, the average of the closing bid
                    and asked prices thereof in the over-the-counter market as
                    reported by the National Association of Securities Dealers
                    Automated Quotation System or any successor system, or if
                    not included therein, the average of the closing bid and
                    asked prices thereof furnished by two members of the
                    National Association of Securities Dealers selected
                    reasonably and in good faith by the Board of Directors for
                    that purpose. In the absence of one or more such quotations,
                    the Market Price for such Equity Interests shall be
                    determined reasonably and in good faith by the Board of
                    Directors.

               "NET PROCEEDS" means the aggregate cash proceeds received by the
Company or any of its Restricted Subsidiaries in respect of any Asset Sale,
which amount is equal to the excess, if any, of:

               (1)  the cash received by the Company or such Restricted
                    Subsidiary (including any cash payments received by way of
                    deferred payment pursuant to, or monetization of, a note or
                    installment receivable or otherwise, but only as and when
                    received) in connection with such disposition, over

               (2)  the sum of:

                    (i)   the amount of any Indebtedness which is secured by
                          such asset and which is required to be repaid in
                          connection with the disposition thereof; plus

                    (ii)  the reasonable out-of-pocket expenses incurred by the
                          Company or such Restricted Subsidiary, as the case may
                          be, in connection with such disposition or in
                          connection with the transfer of such amount from such
                          Restricted Subsidiary to the Company; plus

                                        8
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                    (iii) provisions for taxes, including income taxes,
                          attributable to the disposition of such asset or
                          attributable to required prepayments or repayments of
                          Indebtedness with the proceeds thereof; plus

                    (iv)  if the Company does not first receive a transfer of
                          such amount from the relevant Restricted Subsidiary
                          with respect to the disposition of an asset by such
                          Restricted Subsidiary and such Restricted Subsidiary
                          intends to make such transfer as soon as practicable,
                          the out-of-pocket expenses and taxes that the Company
                          reasonably estimates will be incurred by the Company
                          or such Restricted Subsidiary in connection with such
                          transfer at the time such transfer is expected to be
                          received by the Company (including, without
                          limitation, withholding taxes on the remittance of
                          such amount).

               "NOTES" has the meaning assigned to it in the preamble to this
First Supplemental Indenture. The Initial Notes and any Additional Notes shall
be treated as a single class for all purposes under this First Supplemental
Indenture and the Indenture.

               "PERMITTED INVESTMENTS" means:

               (1)  any Investments in the Company or in a Restricted Subsidiary
                    (other than an Excluded Restricted Subsidiary) of the
                    Company, including without limitation the Guarantee of
                    Indebtedness permitted under Section 2.6(b) of the First
                    Supplemental Indenture (Section 4.9 of the Indenture);

               (2)  any Investments in Cash Equivalents;

               (3)  Investments by the Company or any Restricted Subsidiary of
                    the Company in a Person, if as a result of such Investment;

                    (i)   such Person becomes a Restricted Subsidiary (other
                          than an Excluded Restricted Subsidiary) of the Company
                          or

                    (ii)  such Person is merged, consolidated or amalgamated
                          with or into, or transfers or conveys substantially
                          all of its assets to, or is liquidated into, the
                          Company or a Restricted Subsidiary (other than an
                          Excluded Restricted Subsidiary) of the Company;

               (4)  Investments in assets (including accounts and notes
                    receivable) owned or used in the ordinary course of
                    business;

               (5)  Investments for any purpose related to the Company's records
                    and information management business (including, without
                    limitation, the Company's confidential destruction and
                    fulfillment businesses) in an aggregate outstanding amount
                    not to exceed $10.0 million; and

               (6)  Investments by the Company or a Restricted Subsidiary (other
                    than an Excluded Restricted Subsidiary) in one or more
                    Excluded Restricted Subsidiaries, the aggregate outstanding
                    amount of which does not exceed 10% of the consolidated
                    assets of the Company and its Restricted Subsidiaries.

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               "PERMITTED LIENS" means:

               (1)  Liens existing as of the date of issuance of the Notes;

               (2)  Liens on property or assets of the Company or any Restricted
                    Subsidiary securing Senior Debt;

               (3)  Liens on any property or assets of a Restricted Subsidiary
                    granted in favor of the Company or any Wholly Owned
                    Restricted Subsidiary;

               (4)  Liens securing the Notes or the Guarantees;

               (5)  any interest or title of a lessor under any Capital Lease
                    Obligation or Sale and Leaseback Transaction so long as the
                    Indebtedness, if any, secured by such Lien does not exceed
                    the principal amount of Indebtedness permitted under Section
                    2.6(b) of the First Supplemental Indenture (Section 4.9 of
                    the Indenture);

               (6)  Liens securing Acquired Debt created prior to (and not in
                    connection with or in contemplation of) the incurrence of
                    such Indebtedness by the Company or any Restricted
                    Subsidiary; provided that such Lien does not extend to any
                    property or assets of the Company or any Restricted
                    Subsidiary other than the assets acquired in connection with
                    the incurrence of such Acquired Debt;

               (7)  Liens securing Hedging Obligations permitted to be incurred
                    pursuant to clause (7) of Section 2.6(b) of the First
                    Supplemental Indenture (clause (7) of Section 4.9 of the
                    Indenture);

               (8)  Liens arising from purchase money mortgages and purchase
                    money security interests, or in respect of the construction
                    of property or assets, incurred in the ordinary course of
                    the business of the Company or a Restricted Subsidiary;
                    provided that (i) the related Indebtedness is not secured by
                    any property or assets of the Company or any Restricted
                    Subsidiary other than the property and assets so acquired or
                    constructed and (ii) the Lien securing such Indebtedness is
                    created within 60 days of such acquisition or construction;

               (9)  statutory Liens or landlords' and carriers', warehousemen's,
                    mechanics', suppliers', materialmen's, repairmen's or other
                    like Liens arising in the ordinary course of business and
                    with respect to amounts not yet delinquent or being
                    contested in good faith by appropriate proceedings, if a
                    reserve or other appropriate provision, if any, as shall be
                    required in conformity with GAAP shall have been made
                    therefor;

               (10) Liens for taxes, assessments, government charges or claims
                    with respect to amounts not yet delinquent or that are being
                    contested in good faith by appropriate proceedings
                    diligently conducted, if a reserve or other appropriate
                    provision, if any, as is required in conformity with GAAP
                    has been made therefor;

               (11) Liens incurred or deposits made to secure the performance of
                    tenders, bids, leases, statutory obligations, surety and
                    appeal bonds, government contracts,

                                       10
<Page>

                    performance bonds and other obligations of a like nature
                    incurred in the ordinary course of business (other than
                    contracts for the payment of money);

               (12) easements, rights-of-way, restrictions and other similar
                    charges or encumbrances not interfering in any material
                    respect with the business of the Company or any Restricted
                    Subsidiary incurred in the ordinary course of business;

               (13) Liens arising by reason of any judgment, decree or order of
                    any court so long as such Lien is adequately bonded and any
                    appropriate legal proceedings that may have been duly
                    initiated for the review of such judgment, decree or order
                    shall not have been finally terminated or the period within
                    which such proceedings may be initiated shall not have
                    expired;

               (14) Liens arising under options or agreements to sell assets;

               (15) other Liens securing obligations incurred in the ordinary
                    course of business, which obligations do not exceed $10.0
                    million in the aggregate at any one time outstanding; and

               (16) any extension, renewal or replacement, in whole or in part,
                    of any Lien described in the foregoing clauses (1) through
                    (15); provided that any such extension, renewal or
                    replacement shall not extend to any additional property or
                    assets.

               "PRINCIPAL STOCKHOLDERS" means each of Vincent J. Ryan, Schooner
Capital LLC, C. Richard Reese, Kent P. Dauten, B. Thomas Golisano and their
respective Affiliates.

               "QUALIFIED EQUITY OFFERING" means an offering of Capital Stock,
other than Disqualified Stock, of the Company for Dollars, whether registered or
exempt from registration under the Securities Act.

               "QUALIFIED ISSUER" means:

               (1)  any lender party to the Credit Agreement or

               (2)  any commercial bank:

                    (i)   which has capital and surplus in excess of
                          $500,000,000 and

                    (ii)  the outstanding short-term debt securities of which
                          are rated at least A-2 by Standard & Poor's Rating
                          Group, a division of McGraw-Hill, Inc. or at least P-2
                          by Moody's Investors Service, or carry an equivalent
                          rating by a nationally recognized rating agency if
                          both of the two named rating agencies cease publishing
                          ratings of investments.

               "QUALIFYING SALE AND LEASEBACK TRANSACTION" means any Sale and
Leaseback Transaction between the Company or any of its Restricted Subsidiaries
and any bank, insurance company or other lender or investor providing for the
leasing to the Company or such Restricted Subsidiary of any property (real or
personal) which has been or is to be sold or transferred by the Company or such
Restricted Subsidiary to such lender or investor or to any Person to whom funds
have been or are to be

                                       11
<Page>

advanced by such lender or investor and where the property in question has been
constructed or acquired after the date of the First Supplemental Indenture.

               "REFINANCING INDEBTEDNESS" means new Indebtedness incurred or
given in exchange for, or the proceeds of which are used to repay, redeem,
defease, extend, refinance, renew, replace or refund, other Indebtedness;
provided, however, that:

               (1)  the principal amount of such new Indebtedness shall not
                    exceed the principal amount of Indebtedness so repaid,
                    redeemed, defeased, extended, refinanced, renewed, replaced
                    or refunded (plus the amount of fees, premiums, consent
                    fees, prepayment penalties and expenses incurred in
                    connection therewith);

               (2)  such Refinancing Indebtedness shall have a Weighted Average
                    Life to Maturity equal to or greater than the Weighted
                    Average Life to Maturity of the Indebtedness so repaid,
                    redeemed, defeased, extended, refinanced, renewed, replaced
                    or refunded or shall mature after the maturity date of the
                    Notes;

               (3)  to the extent such Refinancing Indebtedness refinances
                    Indebtedness that has a final maturity date occurring after
                    the initial scheduled maturity date of the Notes, such new
                    Indebtedness shall have a final scheduled maturity not
                    earlier than the final scheduled maturity of the
                    Indebtedness so repaid, redeemed, defeased, extended,
                    refinanced, renewed, replaced or refunded and shall not
                    permit redemption at the option of the holder earlier than
                    the earliest date of redemption at the option of the holder
                    of the Indebtedness so repaid, redeemed, defeased, extended,
                    refinanced, renewed, replaced or refunded;

               (4)  to the extent such Refinancing Indebtedness refinances
                    Indebtedness subordinate to the Notes, such Refinancing
                    Indebtedness shall be subordinated in right of payment to
                    the Notes and to the extent such Refinancing Indebtedness
                    refinances Notes or Indebtedness PARI PASSU with the Notes,
                    such Refinancing Indebtedness shall be PARI PASSU with or
                    subordinated in right of payment to the Notes, in each case
                    on terms at least as favorable to the holders of Notes as
                    those contained in the documentation governing the
                    Indebtedness so repaid, redeemed, defeased, extended,
                    refinanced, renewed, replaced or refunded; and

               (5)  with respect to Refinancing Indebtedness incurred by a
                    Restricted Subsidiary, such Refinancing Indebtedness shall
                    rank no more senior, and shall be at least as subordinated,
                    in right of payment to the Subsidiary Guarantee of such
                    Restricted Subsidiary as the Indebtedness being extended,
                    refinanced, renewed, replaced or refunded.

               "RESTRICTED SUBSIDIARY" means:

               (1)  each direct or indirect Subsidiary of the Company existing
                    on the date of the First Supplemental Indenture (other than
                    Iron Mountain (Netherlands) B.V. and its subsidiaries
                    (including Iron Mountain Europe Limited), Iron Mountain
                    Cayman Ltd. and its subsidiaries, Iron Mountain Mexico, S.A.
                    de R.L. de C.V. and its subsidiaries, Iron Mountain
                    Assurance Corporation and Upper Providence Venture I, L.P.)
                    and

                                       12
<Page>

               (2)  any other direct or indirect Subsidiary of the Company
                    formed, acquired or existing after the date of the First
                    Supplemental Indenture (including an Excluded Restricted
                    Subsidiary),

which, in the case of (1) or (2), is not designated by the Board of Directors as
an "Unrestricted Subsidiary."

               "SALE AND LEASEBACK TRANSACTION" means any transaction or series
of related transactions pursuant to which a Person sells or transfers any
property or asset in connection with the leasing, or the resale against
installment payments, of such property or asset to the seller or transferor.

               "SENIOR BANK DEBT" means all Obligations outstanding under or in
connection with the Credit Agreement (including Guarantees of such Obligations
by Subsidiaries of the Company).

               "SENIOR DEBT" means:

               (1)  the Senior Bank Debt and

               (2)  any other Indebtedness permitted to be incurred by the
                    Company or any Restricted Subsidiary, as the case may be,
                    under the terms of the First Supplemental Indenture or the
                    Indenture, unless the instrument under which such
                    Indebtedness is incurred expressly provides that it is:

                    (i)   on a parity with or subordinated in right of payment
                          to the Notes or

                    (ii)  subordinated to Senior Debt on terms substantially
                          similar to those of the Notes.

               Notwithstanding anything to the contrary in the foregoing, Senior
Debt shall not include:

               (1)  any liability for federal, state, local or other taxes owed
                    or owing by the Company;

               (2)  any Indebtedness of the Company to any of its Subsidiaries
                    or other Affiliates;

               (3)  any trade payables; or

               (4)  any Indebtedness that is incurred in violation of the First
                    Supplemental Indenture or the Indenture, provided that such
                    Indebtedness shall be deemed not to have been incurred in
                    violation of the First Supplemental Indenture or the
                    Indenture for purposes of this clause (4) if, in the case of
                    any obligations under the Credit Agreement, the holders of
                    such obligations or their agent or representative shall have
                    received a representation from the Company to the effect
                    that the incurrence of such Indebtedness does not violate
                    the provisions of the First Supplemental Indenture or the
                    Indenture.

               "TREASURY RATE" means, at any time of computation, the yield to
maturity at such time (as compiled by and published in the most recent Federal
Reserve Statistical Release 11.15(519), which has become publicly available at
least two business days prior to the date of the redemption notice or, if such
Statistical Release is no longer published, any publicly available source of
similar market data) of United States Treasury securities with a constant
maturity most nearly equal to the Make-Whole Average Life;

                                       13
<Page>

provided, however, that if the Make-Whole Average Life is not equal to the
constant maturity of the United States Treasury security for which a weekly
average yield is given, the Treasury Rate shall be obtained by linear
interpolation (calculated to the nearest one-twelfth of a year) from the weekly
average yields of United States Treasury securities for which such yields are
given, except that if the Make-Whole Average Life is less than one year, the
weekly average yield on actually traded United States Treasury securities
adjusted to a constant maturity of one year shall be used.

               "UNRESTRICTED SUBSIDIARY" means:

               (1)  any Subsidiary that is designated by the Board of Directors
                    as an Unrestricted Subsidiary in accordance with Section
                    2.6(h) of the First Supplemental Indenture (Section 4.15 of
                    the Indenture); and

               (2)  any Subsidiary of an Unrestricted Subsidiary.

               As of the date hereof, the following Subsidiaries of the Company
have been designated as Unrestricted Subsidiaries: Iron Mountain (Netherlands)
B.V. and its subsidiaries (including Iron Mountain Europe Limited), Iron
Mountain Cayman Ltd. and its subsidiaries, Iron Mountain Mexico, S.A. de R.L. de
C.V. and its subsidiaries, Iron Mountain Assurance Corporation and Upper
Providence Venture I, L.P.

               "VOTING STOCK" means any class or classes of Capital Stock
pursuant to which the holders thereof have the general voting power under
ordinary circumstances to elect at least a majority of the board of directors,
managers or trustees of any Person (irrespective of whether or not, at the time,
stock of any other class or classes has, or might have, voting power by reason
of the happening of any contingency).

               "WEIGHTED AVERAGE LIFE TO MATURITY" means, when applied to any
Indebtedness at any date, the number of years obtained by dividing:

               (1)  the sum of the products obtained by multiplying (x) the
                    amount of each then remaining installment, sinking fund,
                    serial maturity or other required payment of principal,
                    including payment at final maturity, in respect thereof, by
                    (y) the number of years (calculated to the nearest
                    one-twelfth) that will elapse between such date and the
                    making of such payment, by

               (2)  the then outstanding principal amount of such Indebtedness.

               "WHOLLY OWNED RESTRICTED SUBSIDIARY" means any Restricted
Subsidiary of the Company all of the outstanding Capital Stock or other
ownership interests of which (other than directors' qualifying shares) shall at
the time be owned by the Company or by one or more Wholly Owned Restricted
Subsidiaries of the Company.

               "1996 INDENTURE DATE" means October 1, 1996.

               "1999 INDENTURE DATE" means April 26, 1999.

               "2001 INDENTURE DATE" means April 3, 2001.

                                       14
<Page>

               "8 1/8% NOTES" means Canada Company's 8 1/8% Senior Notes due
2008 issued pursuant to the Indenture dated as of April 7, 1998, by and among
Canada Company, as issuer, the Company and The Bank of New York, as trustee.

               "8 1/4% NOTES" means the Company's 8 1/4% Senior Subordinated
Notes due 2011 issued pursuant to the Indenture dated April 26, 1999, by and
among the Company, certain of its subsidiaries and The Bank of New York, as
trustee.

               "8 3/4% NOTES" means the Company's Senior Subordinated Notes
due 2009 issued pursuant to the Indenture dated October 24, 1997, by and among
the Company, certain of its subsidiaries and The Bank of New York, as trustee.

               "8 5/8% NOTES" means the Company's Senior Subordinated Notes
due 2013 issued pursuant to the Indenture dated April 3, 2001, by and among the
Company, certain of its subsidiaries and The Bank of New York, as trustee.

               "9 1/8% NOTES" means the Company's 9 1/8% Senior Subordinated
Notes due 2007, issued pursuant to the Indenture dated as of July 7, 1997, by
and between the Company, as issuer, and The Bank of New York, as trustee.

               (b)  Other Definitions.

               The definitions of the following terms may be found in the
Sections indicated as follows:

<Table>
<Caption>
                    Term                                  Defined in Section
                    <S>                                   <C>
                    "Affiliate Transaction"               2.6(e)
                    "Asset Sale"                          2.6(j)
                    "Asset Sale Offer"                    2.6(j)
                    "Change of Control Offer"             2.6(k)
                    "Change of Control Payment"           2.6(k)
                    "Change of Control Payment Date"      2.6(k)
                    "Commencement Date"                   2.6(j)
                    "Company"                             Preamble
                    "DTC"                                 2.3
                    "Excess Proceeds"                     2.6(j)
                    "First Supplemental Indenture"        Preamble
                    "Indenture"                           Preamble
                    "Restricted Payments"                 2.6(a)
                    "Trustee"                             Preamble
</Table>

                                   ARTICLE 2.

                           FORM AND TERMS OF THE NOTES

Section 2.1. FORM AND DATING. GENERAL. The Notes and the Trustee's certificate
of authentication shall be substantially in the form of Exhibit A attached
hereto. The Notes may have notations, legends or endorsements required by law,
stock exchange rule or usage. Each Note shall be dated the date of its
authentication. The Notes shall be in denominations of $1,000 and integral
multiples thereof.

                                       15
<Page>

               The terms and provisions contained in the Notes shall constitute,
and are hereby expressly made, a part of the First Supplemental Indenture and
the Indenture and the Company, the Guarantors and the Trustee, by their
execution and delivery of the First Supplemental Indenture and the Indenture (or
in the case of any Guarantor that becomes such after the date hereof, a
supplemental indenture pursuant to Section 2.6(g) of this First Supplemental
Indenture (Section 4.14 of the Indenture)), expressly agree to such terms and
provisions and to be bound thereby. However, to the extent any provision of any
Note conflicts with the express provisions of the Indenture (as supplemented by
this First Supplemental Indenture), the provisions of the Indenture shall govern
and be controlling.

               (b)  GLOBAL NOTES. Notes shall be issued initially in the form of
the Global Notes, which shall be deposited on behalf of the purchasers of the
Notes represented thereby with the Depository at its New York office, and
registered in the name of the Depository or a nominee of the Depository, duly
executed by the Company and authenticated by the Trustee as hereinafter
provided. The aggregate principal amount of the Global Notes may from time to
time be increased or decreased by adjustments made on the records of the Trustee
and the Depository or its nominee as hereinafter provided.

               Each Global Note shall represent such of the outstanding Notes as
shall be specified therein and each shall provide that it represents the
aggregate principal amount of outstanding Notes from time to time endorsed
thereon and that the aggregate amount of outstanding Notes represented thereby
may from time to time be reduced or increased, as appropriate, to reflect
exchanges and redemptions. Any endorsement of a Global Note to reflect the
amount of any increase or decrease in the aggregate principal amount of
outstanding Notes represented thereby shall be made by the Trustee or the
Service Agent, at the direction of the Trustee, in accordance with instructions
given by the Holder thereof as required by Section 2.4 hereof.

               (c)  BOOK-ENTRY PROVISIONS. This Section 2.1(c) shall apply only
to the Global Notes deposited with or on behalf of the Depository.

               The Company shall execute and the Trustee shall, in accordance
with this Section 2.1(c), authenticate and deliver the Global Notes that (i)
shall be registered in the name of the Depository or the nominee of the
Depository and (ii) shall be delivered by the Trustee to the Depository or
pursuant to the Depository's instructions or held by the Service Agent.

               Agent Members shall have no rights either under the First
Supplemental Indenture or the Indenture with respect to any Global Notes held on
their behalf by the Depository or by the Service Agent or under such Global
Notes, and the Depository may be treated by the Company, the Trustee and any
agent of the Company or the Trustee as the absolute owner of such Global Notes
for all purposes whatsoever.

               (d)  DEFINITIVE NOTES. Notes issued in certificated form shall be
substantially in the form of Exhibit A attached hereto (but without including
the text referred to in Section 2.15.3 of the Indenture). Except as provided in
Section 2.4, owners of beneficial interests in the Global Notes will not be
entitled to receive physical delivery of certificated Securities.

Section 2.2. EXECUTION AND AUTHENTICATION.

               The Trustee shall, upon a written order of the Company signed by
an Officer, authenticate up to $100,000,000 aggregate principal amount of
Initial Notes and such amount of Additional Notes as the Company may issue from
time to time.

                                       16
<Page>

Section 2.3. DEPOSITORY AND PAYING AGENT FOR NOTES.

               The Company initially appoints The Depository Trust Company
("DTC") to act as Depository with respect to the Global Notes. The Company
initially appoints the Trustee to act as the Registrar, Paying Agent and Service
Agent with respect to the Global Notes.

Section 2.4. TRANSFER AND EXCHANGE OF NOTES.

               (a)  TRANSFER AND EXCHANGE OF GLOBAL NOTES. The transfer and
exchange of beneficial interests in the Global Notes shall be effected through
the Depository, in accordance with the First Supplemental Indenture and the
Indenture and the procedures of the Depository therefor. Beneficial interests in
the Global Notes may be transferred to Persons who take delivery thereof in the
form of a beneficial interest in the Global Notes.

               (b)  TRANSFER AND EXCHANGE OF DEFINITIVE NOTES. When Definitive
Notes are presented by a Holder to the Registrar with a request:

                    (x)   to register the transfer of the Definitive Notes; or

                    (y)   to exchange such Definitive Notes for an equal
                          principal amount of Definitive Notes of other
                          authorized denominations, the Registrar shall register
                          the transfer or make the exchange as requested if its
                          requirements for such transactions are met; PROVIDED,
                          HOWEVER, that the Definitive Notes presented or
                          surrendered for register of transfer or exchange shall
                          be duly endorsed or accompanied by a written
                          instruction of transfer in form satisfactory to the
                          Registrar duly executed by such Holder or by his
                          attorney, duly authorized in writing.

               (c)  RESTRICTIONS ON TRANSFER AND EXCHANGE OF GLOBAL NOTES.
Notwithstanding any other provision of the First Supplemental Indenture or the
Indenture (other than the provisions set forth in subsection (d) of this Section
2.4), the Global Notes may not be transferred as a whole except by the
Depository to a nominee of the Depository, by a nominee of the Depository to the
Depository or to another nominee of the Depository, or by the Depository or any
such nominee to a successor Depository or a nominee of such successor
Depository.

               (d)  AUTHENTICATION OF DEFINITIVE NOTES IN ABSENCE OF DEPOSITORY.
If at any time:

                    (i)   the Depository for the Notes notifies the Company that
                          the Depository is unwilling or unable to continue as
                          Depository for the Global Notes and a successor
                          Depository for the Global Notes is not appointed by
                          the Company within 90 days after delivery of such
                          notice; or

                    (ii)  the Company at its sole discretion, notifies the
                          Trustee in writing that it elects to cause the
                          issuance of Definitive Notes under the First
                          Supplemental Indenture and the Indenture,

then the Company shall execute, and the Trustee shall, upon receipt of an
authentication order in accordance with Section 2.2 hereof, authenticate and
deliver, Definitive Notes in an aggregate principal amount equal to the
principal amount of the Global Notes in exchange for such Global Notes.

                                       17
<Page>

               (e)  CANCELLATION AND/OR ADJUSTMENT OF THE GLOBAL NOTES. At such
time as all beneficial interests in a particular Global Note have been exchanged
for Definitive Notes or a particular Global Note has been redeemed, repurchased
or canceled in whole and not in part, each such Global Note shall be returned to
or retained and canceled by the Trustee in accordance with Section 2.12 of the
Indenture. At any time prior to such cancellation, if any beneficial interest in
a Global Note is exchanged for or transferred to a Person who will take delivery
thereof in the form of a beneficial interest in another Global Note or for
Definitive Notes, the principal amount of Notes represented by the Global Note
shall be reduced accordingly and an endorsement shall be made on such Global
Note by the Trustee or by the Depository at the direction of the Trustee to
reflect such reduction; and if the beneficial interest is being exchanged for or
transferred to a Person who will take delivery thereof in the form of a
beneficial interest in another Global Note, such other Global Note shall be
increased accordingly and an endorsement will be made on such Global Note by the
Trustee or by the Depository at the direction of the Trustee to reflect such
increase.

               (f)  GENERAL PROVISIONS RELATING TO TRANSFERS AND EXCHANGES.

                    (i)   To permit registrations of transfers and exchanges,
                          the Company shall execute and the Trustee shall
                          authenticate Global Notes and Definitive Notes upon
                          receipt of an Authentication Order in accordance with
                          Section 2.2 hereof or at the Registrar's request.

                    (ii)  No service charge shall be made to a Holder of a
                          Global Note or to a Holder of a Definitive Note for
                          any registration of transfer or exchange, but the
                          Company may require payment of a sum sufficient to
                          cover any transfer tax or similar governmental charge
                          payable in connection therewith (other than any such
                          transfer taxes or similar governmental charge payable
                          upon exchange or transfer pursuant to Section 2.4
                          hereof).

                    (iii) All Global Notes and Definitive Notes issued upon any
                          registration of transfer or exchange of Global Notes
                          or Definitive Notes shall be the valid obligations of
                          the Company, evidencing the same debt, and entitled to
                          the same benefits under the First Supplemental
                          Indenture and the Indenture, as the Global Notes or
                          Definitive Notes surrendered upon such registration of
                          transfer or exchange.

                    (iv)  The Company shall not be required to register the
                          transfer of or to exchange a Note between a record
                          date and the next succeeding interest payment date.

                    (iv)  Prior to due presentment for the registration of a
                          transfer of any Note, the Trustee, any Agent, the
                          Company and any Guarantor may deem and treat the
                          Person in whose name any Note is registered as the
                          absolute owner of such Note for all purposes,
                          including receiving payment of principal of and
                          interest on such Notes, and neither the Trustee, any
                          Agent, the Company nor any Guarantor shall be affected
                          by notice to the contrary.

                                       18
<Page>

                    (v)   The Trustee shall authenticate Definitive Notes and
                          the Global Notes in accordance with the provisions of
                          Section 2.2 hereof and Section 2.3 of the Indenture.

                    (vi)  All certifications, certificates and opinions of
                          counsel required to be submitted to the Registrar
                          pursuant to this Section 2.4 to effect a registration
                          of transfer or exchange may be submitted by facsimile.

Section 2.5. REDEMPTION.

               With respect to the Notes issued under this First Supplemental
Indenture, the following Sections supplement Article III of the Indenture:

               Section 3.7. OPTIONAL REDEMPTION.

               Prior to January 15, 2008, the Notes shall be subject to
redemption at any time at the option of the Company, in whole or in part, upon
not less than 30 nor more than 60 days' notice, at the Make-Whole Price, plus
accrued and unpaid interest, to but excluding the applicable redemption date. On
and after January 15, 2008, the Notes will be subject to redemption at any time
at the option of the Company, in whole or in part, upon not less than 30 nor
more than 60 days' notice, at the redemption price (expressed as percentages of
principal amount) set forth below, plus accrued and unpaid interest, to but
excluding the applicable redemption date, if redeemed during the twelve-month
period beginning on January 15 of the years indicated below:

<Table>
<Caption>
               YEAR                                          PERCENTAGE
               ----                                          ----------
               <S>                                             <C>
               2008......................................      103.875%
               2009......................................      102.583%
               2010......................................      101.292%
               2011 and thereafter.......................      100.000%
</Table>

               Notwithstanding the foregoing, at any time prior to January 15,
2006, the Company may redeem up to 35% of the initial principal amount of the
Notes originally issued with the net proceeds of one or more Qualified Equity
Offerings at a redemption price equal to 107.750% of the principal amount of
such Notes, plus accrued and unpaid interest to but excluding the redemption
date; provided, that at least 65% of the principal amount of Notes originally
issued remains outstanding immediately after the occurrence of any such
redemption and that such redemption occurs within 60 days following the closing
of any such Qualified Equity Offering.

               Section  3.8. MANDATORY REDEMPTION.

               The Company shall not be required to make mandatory redemption
payments or sinking fund payments with respect to the Notes.

               Section  3.9. ASSET SALE OFFERS.

               In the event that the Company shall commence an Asset Sale Offer
pursuant to Section 4.17 hereof, it shall follow the procedures specified below:

                                       19
<Page>

               The Asset Sale Offer shall remain open for 20 Business Days after
the Commencement Date relating to such Asset Sale Offer, except to the extent
required to be extended by applicable law (as so extended, the "OFFER PERIOD").
No later than one Business Day after the termination of the Offer Period (the
"PURCHASE DATE"), the Company shall purchase the principal amount (the "OFFER
AMOUNT") of Notes required to be purchased in such Asset Sale Offer pursuant to
Sections 3.2 and 4.17 hereof or, if less than the Offer Amount has been
tendered, all Notes tendered in response to the Asset Sale Offer.

               If the Purchase Date is on or after an interest payment record
date and on or before the related interest payment date, any interest accrued to
such Purchase Date shall be paid to the Person in whose name a Note is
registered at the close of business on such record date, and no additional
interest shall be payable to Holders who tender Notes pursuant to the Asset Sale
Offer.

               On the Commencement Date of any Asset Sale Offer, the Company
shall send or cause to be sent, by first class mail, a notice to each of the
Holders, with a copy to the Trustee. Such notice, which shall govern the terms
of the Asset Sale Offer, shall contain all instructions and materials necessary
to enable the Holders to tender Notes pursuant to the Asset Sale Offer and shall
state:

               (1)  that the Asset Sale Offer is being made pursuant to this
                    Section 3.9 and Section 4.17 hereof and the length of time
                    the Asset Sale Offer shall remain open;

               (2)  the Offer Amount, the purchase price and the Purchase Date;

               (3)  that any Note not tendered or accepted for payment shall
                    continue to accrue interest;

               (4)  that, unless the Company defaults in the payment of the
                    purchase price, any Note accepted for payment pursuant to
                    the Asset Sale Offer shall cease to accrue interest after
                    the Purchase Date;

               (5)  that Holders electing to have a Note purchased pursuant to
                    any Asset Sale Offer shall be required to surrender the
                    Note, with the form entitled "Option of Holder to Elect
                    Purchase" on the reverse of the Note completed, to the
                    Company, a depositary, if appointed by the Company, or a
                    Paying Agent at the address specified in the notice prior to
                    the close of business on the Business Day preceding the
                    Purchase Date;

               (6)  that Holders shall be entitled to withdraw their election if
                    the Company, depositary or Paying Agent, as the case may be,
                    receives, not later than the close of business on the
                    Business Day preceding the termination of the Offer Period,
                    a facsimile transmission or letter setting forth the name of
                    the Holder, the principal amount of the Note the Holder
                    delivered for purchase and a statement that such Holder is
                    withdrawing such Holder's election to have the Note
                    purchased;

               (7)  that, if the aggregate principal amount of Notes surrendered
                    by Holders exceeds the Offer Amount, the Trustee shall
                    select the Notes to be purchased on a PRO RATA basis (with
                    such adjustments as may be deemed to be appropriate by the
                    Company so that only Notes in denominations of $1,000, or
                    integral multiples thereof, shall be purchased); and

                                       20
<Page>

               (8)  that Holders whose Notes were purchased only in part shall
                    be issued new Notes equal in principal amount to the
                    unpurchased portion of the Notes surrendered.

               On or before 12:00 noon on each Purchase Date, the Company shall
irrevocably deposit with the Trustee or Paying Agent in immediately available
funds the aggregate purchase price with respect to a principal amount of Notes
equal to the Offer Amount, together with accrued interest thereon, to be held
for payment in accordance with the terms of this Section 3.9. On the Purchase
Date, the Company shall, to the extent lawful, (i) accept for payment, on a PRO
RATA basis to the extent necessary, an aggregate principal amount equal to the
Offer Amount of Notes and other notes (in accordance with the terms of Section
4.17 of the Indenture) tendered pursuant to the Asset Sale Offer, or if less
than the Offer Amount has been tendered, all Notes and such other notes or
portions thereof tendered, (ii) deliver or cause the Paying Agent or depositary,
as the case may be, to deliver to the Trustee Notes so accepted and (iii)
deliver to the Trustee an Officers' Certificate stating that such Notes or
portions thereof were accepted for payment by the Company in accordance with the
terms of this Section 3.9. The Company, depositary or Paying Agent, as the case
may be, shall promptly (but in any case not later than three Business Days after
the Purchase Date) mail or deliver to each tendering Holder an amount equal to
the purchase price with respect to the Notes tendered by such Holder and
accepted by the Company for purchase, and the Company shall promptly issue a new
Note, and the Trustee shall authenticate and mail or deliver such new Note, to
such Holder, equal in principal amount to any unpurchased portion of such
Holder's Notes surrendered. Any Note not accepted in the Asset Sale Offer shall
be promptly mailed or delivered by the Company to the Holder thereof. The
Company shall publicly announce in a newspaper of general circulation the
results of the Asset Sale Offer on the Purchase Date.

               The Asset Sale Offer shall be made by the Company in compliance
with all applicable laws, including, without limitation, Regulation 14E of the
Exchange Act and the rules thereunder, to the extent applicable, and all other
applicable federal and state securities laws.

               Each purchase pursuant to this Section 3.9 shall be made pursuant
to the provisions of Sections 3.1 through 3.6 hereof to the extent applicable.

               In the event the amount of Excess Proceeds to be applied to an
Asset Sale Offer would result in the purchase of a principal amount of Notes
which is not evenly divisible by $1,000, the Trustee shall promptly refund to
the Company the portion of such Excess Proceeds that is not necessary to
purchase the immediately lesser principal amount of Notes that is so divisible.

Section 2.6. COVENANTS.

               With respect to the Notes issued under this First Supplemental
Indenture, Sections 2.6(a) through 2.6(k) are added to Article IV of the
Indenture.

               (a) RESTRICTED PAYMENTS.

               Section 4.8. RESTRICTED PAYMENTS. The Company shall not, and
shall not permit any of its Restricted Subsidiaries to, directly or indirectly:

               (1)  declare or pay any dividend or make any distribution on
                    account of the Company's or any of its Restricted
                    Subsidiaries' Equity Interests (other than dividends or
                    distributions payable in Equity Interests (other than
                    Disqualified Stock) of the Company or such Restricted
                    Subsidiary or dividends or distributions payable to the
                    Company or any Restricted Subsidiary);

                                       21
<Page>

               (2)  purchase, redeem or otherwise acquire or retire for value
                    any Equity Interests of the Company or any Restricted
                    Subsidiary or other Affiliate of the Company (other than any
                    such Equity Interests owned by the Company or any Restricted
                    Subsidiary);

               (3)  purchase, redeem or otherwise acquire or retire prior to
                    scheduled maturity for value any Indebtedness that is
                    subordinated in right of payment to the Notes; or

               (4)  make any Investment other than a Permitted Investment (all
                    such payments and other actions set forth in clauses (1)
                    through (4) above being collectively referred to as
                    "RESTRICTED PAYMENTS");

unless, at the time of such Restricted Payment:

                    (i)   no Default or Event of Default shall have occurred and
                          be continuing or would occur as a consequence thereof;
                          and

                    (ii)  the Company would, at the time of such Restricted
                          Payment and after giving pro forma effect thereto,
                          have been permitted to incur at least $1.00 of
                          additional Indebtedness pursuant to the test set forth
                          in the first paragraph of Section 4.9 of the
                          Indenture; and

                    (iii) such Restricted Payment, together with the aggregate
                          of all other Restricted Payments made by the Company
                          and its Restricted Subsidiaries after the 1996
                          Indenture Date is less than (x) the cumulative EBITDA
                          of the Company, minus 1.75 times the cumulative
                          Consolidated Interest Expense of the Company, in each
                          case for the period (taken as one accounting period)
                          from June 30, 1996, to the end of the Company's most
                          recently ended fiscal quarter for which internal
                          financial statements are available at the time of such
                          Restricted Payment, plus (y) the aggregate net Equity
                          Proceeds received by the Company from the issuance or
                          sale since the 1996 Indenture Date of Equity Interests
                          of the Company or of debt securities of the Company
                          that have been converted into such Equity Interests
                          (other than Equity Interests or convertible debt
                          securities sold to a Restricted Subsidiary of the
                          Company and other than Disqualified Stock or debt
                          securities that have been converted into Disqualified
                          Stock), plus (z) $2.0 million.

               The foregoing provisions will not prohibit:

               (1)  the payment of any dividend within 60 days after the date of
                    declaration thereof, if at said date of declaration such
                    payment would have complied with the provisions of the
                    Indenture;

               (2)  the redemption, repurchase, retirement or other acquisition
                    or retirement for value of any Equity Interests of the
                    Company in exchange for, or with the net cash proceeds of,
                    the substantially concurrent sale (other than to a
                    Restricted Subsidiary of the Company) of other Equity
                    Interests of the Company (other than any Disqualified
                    Stock);

                                       22
<Page>

               (3)  the defeasance, redemption, repurchase, retirement or other
                    acquisition or retirement for value of Indebtedness that is
                    subordinated in right of payment to the Notes in exchange
                    for, or with the net cash proceeds of, a substantially
                    concurrent issuance and sale (other than to a Restricted
                    Subsidiary of the Company) of Equity Interests of the
                    Company (other than Disqualified Stock);

               (4)  the defeasance, redemption, repurchase, retirement or other
                    acquisition or retirement for value of Indebtedness that is
                    subordinated in right of payment to the Notes in exchange
                    for, or with the net cash proceeds of, a substantially
                    concurrent issue and sale (other than to the Company or any
                    of its Restricted Subsidiaries) of Refinancing Indebtedness;

               (5)  the repurchase of any Indebtedness subordinated in right of
                    payment to the Notes at a purchase price not greater than
                    101% of the principal amount of such Indebtedness in the
                    event of a Change of Control in accordance with provisions
                    similar to the covenant set forth in Section 4.18 of the
                    Indenture, provided that prior to or contemporaneously with
                    such repurchase the Company has made the Change of Control
                    Offer as provided in such covenant with respect to the Notes
                    and has repurchased all Notes validly tendered for payment
                    in connection with such Change of Control Offer; and

               (6)  additional payments to current or former employees or
                    directors of the Company for repurchases of stock, stock
                    options or other equity interests, provided that the
                    aggregate amount of all such payments under this clause (6)
                    does not exceed $0.5 million in any year and $2.0 million in
                    the aggregate.

               The Restricted Payments described in clauses (2), (3), (5) and
(6) of the immediately preceding paragraph shall be Restricted Payments that
shall be permitted to be taken in accordance with such paragraph but shall
reduce the amount that would otherwise be available for Restricted Payments
under clause (iii) of the first paragraph of this Section, and the Restricted
Payments described in clauses (1) and (4) of the immediately preceding paragraph
shall be Restricted Payments that shall be permitted to be taken in accordance
with such paragraph and shall not reduce the amount that would otherwise be
available for Restricted Payments under clause (iii) of the first paragraph of
this Section.

               If an Investment results in the making of a Restricted Payment,
the aggregate amount of all Restricted Payments deemed to have been made as
calculated under the foregoing provision shall be reduced by the amount of any
net reduction in such Investment (resulting from the payment of interest or
dividends, loan repayment, transfer of assets or otherwise) to the extent such
net reduction is not included in the Company's EBITDA; PROVIDED, HOWEVER, that
the total amount by which the aggregate amount of all Restricted Payments may be
reduced may not exceed the lesser of (a) the cash proceeds received by the
Company and its Restricted Subsidiaries in connection with such net reduction
and (b) the initial amount of such Investment.

               If the aggregate amount of all Restricted Payments calculated
under the foregoing provision includes an Investment in an Unrestricted
Subsidiary or other Person that thereafter becomes a Restricted Subsidiary, such
Investment will no longer be counted as a Restricted Payment for purposes of
calculating the aggregate amount of Restricted Payments. For the purpose of
making any calculations under the Indenture:

                                       23
<Page>

               (1)  an Investment shall include the fair market value of the net
                    assets of any Restricted Subsidiary at the time that such
                    Restricted Subsidiary is designated an Unrestricted
                    Subsidiary and shall exclude the fair market value of the
                    net assets of any Unrestricted Subsidiary that is designated
                    as a Restricted Subsidiary;

               (2)  any property transferred to or from an Unrestricted
                    Subsidiary shall be valued at fair market value at the time
                    of such transfer, provided that, in each case, the fair
                    market value of an asset or property is as determined by the
                    Board of Directors in good faith; and

               (3)  subject to the foregoing, the amount of any Restricted
                    Payment, if other than cash, shall be determined by the
                    Board of Directors, whose good faith determination shall be
                    conclusive.

               The Board of Directors may designate a Restricted Subsidiary to
be an Unrestricted Subsidiary in compliance with the Section 4.15 of the
Indenture. Upon such designation, all outstanding Investments by the Company and
its Restricted Subsidiaries (except to the extent repaid in cash) in the
Subsidiary so designated will be deemed to be Restricted Payments made at the
time of such designation and will reduce the amount available for Restricted
Payments under the first paragraph of this covenant. Such designation will only
be permitted if such Restricted Payment would be permitted at such time and if
such Restricted Subsidiary otherwise meets the definition of an Unrestricted
Subsidiary.

               (b) INCURRENCE OF INDEBTEDNESS AND ISSUANCE OF PREFERRED STOCK.

               Section 4.9. INCURRENCE OF INDEBTEDNESS AND ISSUANCE OF PREFERRED
STOCK. The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, directly or indirectly, create, incur, issue, assume, guaranty
or otherwise become directly or indirectly liable with respect to (collectively,
"INCUR") any Indebtedness (including Acquired Debt) and the Company shall not
permit any of its Restricted Subsidiaries to issue any shares of preferred
stock; provided, however, that the Company may incur Indebtedness and may permit
a Restricted Subsidiary to incur Indebtedness if at the time of such incurrence
and after giving effect thereto the Leverage Ratio would be less than 6.5 to
1.0.

               The foregoing limitations shall not apply to:

               (1)  the incurrence by the Company or any Restricted Subsidiary
                    of Senior Bank Debt in an aggregate amount not to exceed
                    $100.0 million at any one time outstanding;

               (2)  the issuance by the Restricted Subsidiaries of Subsidiary
                    Guarantees;

               (3)  the incurrence by the Company and its Restricted
                    Subsidiaries of the Existing Indebtedness;

               (4)  the issuance by the Company of the Notes;

               (5)  the incurrence by the Company and its Restricted
                    Subsidiaries of Capital Lease Obligations and/or additional
                    Indebtedness constituting purchase money obligations up to
                    an aggregate of $5.0 million at any one time outstanding,
                    provided that the Liens securing such Indebtedness
                    constitute Permitted Liens;

                                       24
<Page>

               (6)  the incurrence of Indebtedness between (i) the Company and
                    its Restricted Subsidiaries and (ii) the Restricted
                    Subsidiaries;

               (7)  Hedging Obligations that are incurred for the purpose of
                    fixing or hedging interest rate risk with respect to any
                    floating rate Indebtedness that is permitted by the terms of
                    the Indenture to be outstanding;

               (8)  the incurrence by the Company and its Restricted
                    Subsidiaries of Indebtedness arising out of letters of
                    credit, performance bonds, surety bonds and bankers'
                    acceptances incurred in the ordinary course of business up
                    to an aggregate of $5.0 million at any one time outstanding;

               (9)  the incurrence by the Company and its Restricted
                    Subsidiaries of Indebtedness consisting of guarantees,
                    indemnities or obligations in respect of purchase price
                    adjustments in connection with the acquisition or
                    disposition of assets, including, without limitation, shares
                    of Capital Stock; and

               (10) the incurrence by the Company and its Restricted
                    Subsidiaries of Refinancing Indebtedness issued in exchange
                    for, or the proceeds of which are used to repay, redeem,
                    defease, extend, refinance, renew, replace or refund,
                    Indebtedness referred to in clauses (2) through (5) above,
                    and this clause (10) or that was otherwise permitted to be
                    incurred pursuant to the test set forth in the first
                    paragraph of this Section 4.9.

               (c)  LIENS.

               Section 4.10. LIENS. Neither the Company nor any of its
Restricted Subsidiaries may directly or indirectly create, incur, assume or
suffer to exist any Lien (other than a Permitted Lien) upon any property or
assets now owned or hereafter acquired, or any income, profits or proceeds
therefrom, or assign or otherwise convey any right to receive income therefrom,
unless (a) in the case of any Lien securing any Indebtedness that is subordinate
to the Notes, the Notes are secured by a Lien on such property, assets or
proceeds that is senior in priority to such Lien and (b) in the case of any
other Lien, the Notes are equally and ratably secured with the obligation or
liability secured by such Lien.

               (d)  DIVIDEND AND OTHER PAYMENT RESTRICTIONS AFFECTING RESTRICTED
SUBSIDIARIES.


               Section 4.11. DIVIDEND AND OTHER PAYMENT RESTRICTIONS AFFECTING
RESTRICTED SUBSIDIARIES. The Company shall not, and shall not permit any of its
Restricted Subsidiaries to, directly or indirectly, create or otherwise cause or
suffer to exist or become effective any encumbrance or restriction on the
ability of any Restricted Subsidiary to:

               (1)  (i) pay dividends or make any other distributions to the
                    Company or any of its Restricted Subsidiaries (A) on its
                    Capital Stock or (B) with respect to any other interest or
                    participation in, or measured by, its profits, or (ii) pay
                    any Indebtedness owed to the Company or any of its
                    Restricted Subsidiaries;

               (2)  make loans or advances to the Company or any of its
                    Restricted Subsidiaries; or

               (3)  transfer any of its properties or assets to the Company or
                    any of its Restricted Subsidiaries.

                                       25
<Page>

               However, the preceding restrictions will not apply to
encumbrances or restrictions existing under or by reason of:

               (1)  Existing Indebtedness;

               (2)  the Credit Agreement as in effect as of the date of the
                    Indenture, and any amendments, modifications, restatements,
                    renewals, increases, supplements, refundings, replacements
                    or refinancing thereof, provided that such amendments,
                    modifications, restatements, renewals, increases,
                    supplements, refundings, replacements or refinancings are no
                    more restrictive in the aggregate with respect to such
                    dividend and other payment restrictions than those contained
                    in the Credit Agreement as in effect on the date of the
                    Indenture;

               (3)  the Indenture and the Notes;

               (4)  applicable law;

               (5)  any instrument governing Indebtedness or Capital Stock of a
                    Person acquired by the Company or any of its Restricted
                    Subsidiaries as in effect at the time of such acquisition
                    (except to the extent such Indebtedness was incurred in
                    connection with or in contemplation of such acquisition),
                    which encumbrance or restriction is not applicable to any
                    Person, or the properties or assets of any Person, other
                    than the Person, or the property or assets of the Person, so
                    acquired, provided that the EBITDA of such Person is not
                    taken into account in determining whether such acquisition
                    was permitted by the terms of the Indenture;

               (6)  customary non-assignment provisions in leases entered into
                    in the ordinary course of business and consistent with past
                    practices;

               (7)  restrictions on the transfer of property subject to purchase
                    money obligations or Capital Lease Obligations otherwise
                    permitted by clause (5) of Section 4.9 of the Indenture;

               (8)  permitted Refinancing Indebtedness, provided that the
                    restrictions contained in the agreements governing such
                    Refinancing Indebtedness are no more restrictive in the
                    aggregate than those contained in the agreements governing
                    the Indebtedness being refinanced; or

               (9)  any agreement or instrument governing Indebtedness of an
                    Excluded Restricted Subsidiary provided that (i) at the time
                    such agreement or instrument is entered into, such Excluded
                    Restricted Subsidiary and its Restricted Subsidiaries have a
                    Leverage Ratio of less than 6.5 to 1.0 and (ii) neither such
                    Excluded Restricted Subsidiary nor any of its Restricted
                    Subsidiaries shall, directly or indirectly, incur any
                    Indebtedness (including Acquired Debt) unless at the time of
                    such incurrence and after giving effect thereto, the
                    Leverage Ratio for such Excluded Restricted Subsidiary and
                    its Restricted Subsidiaries would be less than 6.5 to 1.0.
                    For purposes of determining the Leverage Ratio under this
                    clause (9) only, all references to the "Company" and its
                    "Restricted Subsidiaries" or similar references in the
                    definition of "Leverage Ratio" and other defined terms

                                       26
<Page>

                    necessary to determine the Leverage Ratio shall be deemed to
                    refer to such Excluded Restricted Subsidiary and its
                    Restricted Subsidiaries, respectively.

               (e) TRANSACTIONS WITH AFFILIATES.

               Section 4.12. TRANSACTIONS WITH AFFILIATES. The Company shall
not, and shall not permit any of its Restricted Subsidiaries to, sell, lease,
transfer or otherwise dispose of any of its properties or assets to, or purchase
any property or assets from, or enter into any contract, agreement,
understanding, loan, advance or guarantee with, or for the benefit of, any
Affiliate (each of the foregoing, an "AFFILIATE TRANSACTION"), unless:

               (a)  such Affiliate Transaction is on terms that are no less
                    favorable to the Company or the relevant Restricted
                    Subsidiary than those that would have been obtained in a
                    comparable transaction by the Company or such Restricted
                    Subsidiary with a non-Affiliated Person and

               (b)  the Company delivers to the Trustee:

                    (i)   with respect to any Affiliate Transaction involving
                          aggregate payments in excess of $5.0 million, a
                          resolution of the Board of Directors set forth in an
                          Officers' Certificate certifying that such Affiliate
                          Transaction complies with clause (a) above and such
                          Affiliate Transaction is approved by a majority of the
                          disinterested members of the Board of Directors and

                    (ii)  with respect to any Affiliate Transaction involving
                          aggregate payments in excess of $10.0 million, an
                          opinion as to the fairness to the Company or such
                          Restricted Subsidiary from a financial point of view
                          issued by an investment banking firm of national
                          standing.

               The following items shall not be deemed Affiliate Transactions
and therefore, will not be subject to the provisions of the prior paragraph:

               (1)  any employment agreement entered into by the Company or any
                    of its Restricted Subsidiaries in the ordinary course of
                    business and consistent with the past practice of the
                    Company or such Restricted Subsidiary;

               (2)  transactions between or among the Company and/or its
                    Restricted Subsidiaries;

               (3)  transactions permitted by the provisions of Section 4.8 of
                    the Indenture; and

               (4)  the grant of stock, stock options or other equity interests
                    to employees and directors of the Company and any Restricted
                    Subsidiary in accordance with duly adopted Company stock
                    grant, stock option and similar plans.

          The provisions set forth in clause (b) above shall not apply to sales
of inventory by the Company or any Restricted Subsidiary to any Affiliate in the
ordinary course of business. The provisions of clause (b) (ii) above shall not
apply to loans or advances to the Company or any Restricted Subsidiary from, or
equity investments in the Company or any Restricted Subsidiary by, any Affiliate
to the extent permitted by the provisions of Section 4.9 of the Indenture.

                                       27
<Page>

               (f)  CERTAIN SENIOR SUBORDINATED DEBT.

               Section 4.13. CERTAIN SENIOR SUBORDINATED DEBT. The Company shall
not incur any Indebtedness that is subordinated or junior in right of payment to
any Senior Debt of the Company and senior in any respect in right of payment to
the Notes. The Company shall not permit any Restricted Subsidiary to incur any
Indebtedness that is subordinated or junior in right of payment to its Senior
Debt and senior in any respect in right of payment to its Subsidiary Guarantee.

               (g)  ADDITIONAL SUBSIDIARY GUARANTEES.

               Section 4.14. ADDITIONAL SUBSIDIARY GUARANTEES. If any entity
(other than an Excluded Restricted Subsidiary) shall become a Restricted
Subsidiary after the date of the First Supplemental Indenture, then such
Restricted Subsidiary shall execute a supplemental indenture in the form of
Exhibit B attached hereto, pursuant to which it shall provide a Subsidiary
Guarantee and deliver an Opinion of Counsel with respect thereto, in accordance
with the terms of the Indenture.

               No Restricted Subsidiary (including any Excluded Restricted
Subsidiary) shall consolidate with or merge with or into (whether or not such
Restricted Subsidiary is the surviving Person), another Person (other than the
Company) whether or not affiliated with such Restricted Subsidiary unless:

               (1)  subject to the provisions of the following paragraph, the
                    Person formed by or surviving any such consolidation or
                    merger (if other than such Restricted Subsidiary) assumes
                    all the obligations of such Restricted Subsidiary under its
                    Subsidiary Guarantee (except in the case of an Excluded
                    Restricted Subsidiary) pursuant to a supplemental indenture
                    in form and substance reasonably satisfactory to the
                    Trustee;

               (2)  immediately after giving effect to such transaction, no
                    Default or Event of Default exists; and

               (3)  such Restricted Subsidiary, or any Person formed by or
                    surviving any such consolidation or merger, would be
                    permitted to incur, immediately after giving effect to such
                    transaction, at least $1.00 of additional Indebtedness
                    pursuant to the test set forth in the first paragraph of
                    Section 4.9 of the Indenture.

In the event of:

               (1)  a sale or other disposition of all of the assets of any
                    Restricted Subsidiary, by way of merger, consolidation or
                    otherwise;

               (2)  a sale or other disposition of all of the capital stock of
                    any Restricted Subsidiary; or

               (3)  the designation of a Restricted Subsidiary as an
                    Unrestricted Subsidiary in accordance with the terms of
                    Section 4.15 of the Indenture,

then such Restricted Subsidiary (in the event of a sale or other disposition, by
way of such a merger, consolidation or otherwise, of all of the capital stock of
such Restricted Subsidiary or in the event of the designation of such Restricted
Subsidiary as an Unrestricted Subsidiary) or the Person acquiring the property
(in the event of a sale or other disposition of all of the assets of such
Restricted Subsidiary) will

                                       28
<Page>

be released and relieved of any obligations under its Subsidiary Guarantee,
provided that the Net Proceeds of such sale or other disposition are applied in
accordance with the applicable provisions of Section 4.17 of the Indenture.

               (h) DESIGNATION OF UNRESTRICTED SUBSIDIARIES.

               Section 4.15. DESIGNATION OF UNRESTRICTED SUBSIDIARIES. The Board
of Directors may designate any Subsidiary (including any Restricted Subsidiary
or any newly acquired or newly formed Subsidiary) to be an Unrestricted
Subsidiary so long as:

               (1)  neither the Company nor any Restricted Subsidiary is
                    directly or indirectly liable for any Indebtedness of such
                    Subsidiary;

               (2)  no default with respect to any Indebtedness of such
                    Subsidiary would permit (upon notice, lapse of time or
                    otherwise) any holder of any other Indebtedness of the
                    Company or any Restricted Subsidiary to declare a default on
                    such other Indebtedness or cause the payment thereof to be
                    accelerated or payable prior to its stated maturity;

               (3)  any Investment in such Subsidiary deemed to be made as a
                    result of designating such Subsidiary an Unrestricted
                    Subsidiary will not violate the provisions of Section 4.8 of
                    the Indenture;

               (4)  neither the Company nor any Restricted Subsidiary has a
                    contract, agreement, arrangement, understanding or
                    obligation of any kind, whether written or oral, with such
                    Subsidiary other than (A) those that might be obtained at
                    the time from Persons who are not Affiliates of the Company
                    or (B) administrative, tax sharing and other ordinary course
                    contracts, agreements, arrangements and understandings or
                    obligations entered into in the ordinary course of business;
                    and

               (5)  neither the Company nor any Restricted Subsidiary has any
                    obligation to subscribe for additional shares of Capital
                    Stock or other Equity Interests in such Subsidiary, or to
                    maintain or preserve such Subsidiary's financial condition
                    or to cause such Subsidiary to achieve certain levels of
                    operating results other than as permitted under Section 4.8
                    of the Indenture.

               Notwithstanding the foregoing, the Company may not designate as
an Unrestricted Subsidiary any Subsidiary which, on the 1999 Indenture Date, was
a Significant Subsidiary, and may not sell, transfer or otherwise dispose of any
properties or assets of any such Significant Subsidiary to an Unrestricted
Subsidiary, other than in the ordinary course of business, in each case other
than Iron Mountain Global, Inc. and its Subsidiaries (including without
limitation Iron Mountain Europe Limited and its Subsidiaries).

               The Board of Directors may designate any Unrestricted Subsidiary
as a Restricted Subsidiary; provided that such designation will be deemed to be
an incurrence of Indebtedness by a Restricted Subsidiary of any outstanding
Indebtedness of such Unrestricted Subsidiary and such designation will only be
permitted if:

               (1)  such Indebtedness is permitted under Section 4.9 of the
                    Indenture and

                                       29
<Page>

               (2)  no Default or Event of Default would occur as a result of
                    such designation.

               (i)  LIMITATION ON SALE AND LEASEBACK TRANSACTIONS.

               Section 4.16. LIMITATION ON SALE AND LEASEBACK TRANSACTIONS. The
Company will not, and will not permit any Restricted Subsidiary to, enter into
any Sale and Leaseback Transaction unless:

               (1)  the consideration received in such Sale and Leaseback
                    Transaction is at least equal to the fair market value of
                    the property sold, as determined by a resolution of the
                    Board of Directors; and

               (2)  the Company or such Restricted Subsidiary could incur the
                    Attributable Indebtedness in respect of such Sale and
                    Leaseback Transaction in compliance with Section 4.9 of the
                    Indenture.

               (j)  ASSET SALES.

               Section 4.17. ASSET SALES. The Company shall not, and shall not
permit any of its Restricted Subsidiaries to:

               (1)  sell, lease, convey or otherwise dispose of any assets
                    (including by way of a Sale and Leaseback Transaction, but
                    excluding a Qualifying Sale and Leaseback Transaction) other
                    than sales of inventory in the ordinary course of business
                    (provided that the sale, lease, conveyance or other
                    disposition of all or substantially all of the assets of the
                    Company will be governed by the provisions of Section 4.18
                    of the Indenture and/or the provisions of Section 5.1 of the
                    Indenture and not by the provisions of this Section 4.17);
                    or

               (2)  issue or sell Equity Interests of any of its Restricted
                    Subsidiaries

that in the case of either clause (1) or (2) above, whether in a single
transaction or a series of related transactions:

               (i)  have a fair market value in excess of $2.0 million; or

               (ii) result in Net Proceeds in excess of $2.0 million (each of
                    the foregoing, an "ASSET SALE"), unless (x) the Company (or
                    the Restricted Subsidiary, as the case may be) receives
                    consideration at the time of such Asset Sale at least equal
                    to the fair market value (evidenced by an Officers'
                    Certificate delivered to the Trustee, and for Asset Sales
                    having a fair market value or resulting in Net Proceeds in
                    excess of $10.0 million, evidenced by a resolution of the
                    Board of Directors set forth in an Officers' Certificate
                    delivered to the Trustee) of the assets sold or otherwise
                    disposed of and (y) at least 75% of the consideration
                    therefor received by the Company or such Restricted
                    Subsidiary is in the form of cash or like-kind assets (in
                    each case as determined in good faith by the Company,
                    evidenced by a resolution of the Board of Directors and
                    certified by an Officers' Certificate delivered to the
                    Trustee);

provided, however, that the amount of:

                                       30
<Page>

               (A)  any liabilities (as shown on the Company's or such
                    Restricted Subsidiary's most recent balance sheet or in the
                    notes thereto) of the Company or such Restricted Subsidiary
                    (other than liabilities that are by their terms subordinated
                    to the Notes or any Subsidiary Guarantee) that are assumed
                    by the transferee of any such assets; and

               (B)  any notes or other obligations received by the Company or
                    such Restricted Subsidiary from such transferee that are
                    immediately converted by the Company or such Restricted
                    Subsidiary into cash (to the extent of the cash received) or
                    Cash Equivalents,

shall be deemed to be cash for purposes of this provision; and provided,
further, that the 75% limitation referred to in the foregoing clause (ii) (y)
shall not apply to any Asset Sale in which the cash portion of the consideration
received therefrom is equal to or greater than what the after-tax proceeds would
have been had such Asset Sale complied with the aforementioned 75% limitation.

               A transfer of assets or issuance of Equity Interests by the
Company to a Wholly Owned Restricted Subsidiary or by a Wholly Owned Restricted
Subsidiary to the Company or to another Wholly Owned Restricted Subsidiary will
not be deemed to be an Asset Sale.

               Within 360 days of any Asset Sale, the Company may, at its
option, apply an amount equal to the Net Proceeds from such Asset Sale either:

               (1)  to permanently reduce Senior Debt; or

               (2)  to an investment in a Restricted Subsidiary or in another
                    business or capital expenditure or other long-term/tangible
                    assets, in each case, in the same line of business as the
                    Company or any of its Restricted Subsidiaries was engaged in
                    on the date of the First Supplemental Indenture or in
                    businesses similar or reasonably related thereto.

               Pending the final application of any such Net Proceeds, the
Company may temporarily reduce Senior Bank Debt or otherwise invest such Net
Proceeds in any manner that is not prohibited by the Indenture. Any Net Proceeds
from such Asset Sale that are not applied or invested as provided in the first
sentence of this paragraph will be deemed to constitute "EXCESS PROCEEDS." When
the aggregate amount of Excess Proceeds exceeds $10.0 million, the Company shall
make an offer to all Holders of the Notes, all holders of the 9 1/8% Notes,
the 8 1/4% Notes, the 8 1/8% Notes, the 8 3/4% Notes and the 8 5/8%
Notes and the holders of any future Indebtedness ranking PARI PASSU with the
Notes, which Indebtedness contains similar provisions requiring the Company to
repurchase such Indebtedness (an "ASSET SALE OFFER"), to purchase the maximum
principal amount of Notes and such other Indebtedness that may be purchased out
of the Excess Proceeds, at an offer price in cash in an amount equal to 100% of
the principal amount thereof plus accrued and unpaid interest, if any, to the
date of purchase, in accordance with the procedures set forth in the Indenture.
To the extent that the aggregate amount of Notes and other PARI PASSU
Indebtedness (including the 9 1/8% Notes, the 8 1/4% Notes, the 8 1/8%
Notes, the 8 3/4% Notes and the 8 5/8% Notes) tendered pursuant to an Asset
Sale Offer is less than the Excess Proceeds, the Company may use any remaining
Excess Proceeds for general corporate purposes. If the aggregate principal
amount of Notes and such other Indebtedness surrendered by Holders thereof
exceeds the amount of Excess Proceeds, the Trustee shall select the Notes and
such other Indebtedness to be

                                       31
<Page>

purchased on a pro rata basis. Upon completion of such offer to purchase, the
amount of Excess Proceeds shall be reset at zero.

               The Company shall comply with the requirements of Rule 14e-1
under the Exchange Act and any other securities laws and regulations thereunder
to the extent those laws and regulations are applicable in connection with each
repurchase of Notes pursuant to an Asset Sale Offer. To the extent that the
provisions of any securities laws or regulations conflict with the provisions of
this Section 4.17, the Company shall comply with the applicable securities laws
and regulations and shall not be deemed to have breached its obligations under
the Asset Sale provisions of the Indenture by virtue of such conflict.

               An Asset Sale Offer shall be made pursuant to the provisions of
Section 3.9 hereof. No later than the date which is five Business Days after the
date on which the aggregate amount of Excess Proceeds exceeds $10.0 million, the
Company shall notify the Trustee of such Asset Sale Offer and provide the
Trustee with an Officers' Certificate setting forth the calculations used in
determining the amount of Net Proceeds to be applied to the purchase of Notes.
The Company shall commence or cause to be commenced the Asset Sale Offer on a
date no later than 15 Business Days after such notice (the "COMMENCEMENT DATE").

               (k)  CHANGE OF CONTROL OFFER.

               Section 4.18. CHANGE OF CONTROL OFFER.

               (a)  Upon the occurrence of a Change of Control, each Holder of
Notes shall have the right to require the Company to repurchase all or any part
(equal to $1,000 or an integral multiple thereof) of such Holder's Notes
pursuant to the offer described below (the "CHANGE OF CONTROL OFFER") at an
offer price in cash equal to 101% of the aggregate principal amount thereof plus
accrued and unpaid interest to but excluding the date of repurchase (the "CHANGE
OF CONTROL PAYMENT").

               Within 30 calendar days following any Change of Control, the
Company shall mail a notice to each Holder, with a copy to the Trustee, stating:

               (1)  that the Change of Control Offer is being made pursuant to
                    this Section 4.18 and that all Notes tendered shall be
                    accepted for payment;

               (2)  the purchase price and the purchase date, which shall be no
                    earlier than 30 calendar days nor later than 60 calendar
                    days from the date such notice is mailed (the "CHANGE OF
                    CONTROL PAYMENT DATE");

               (3)  that any Note not tendered shall continue to accrue
                    interest;

               (4)  that, unless the Company defaults in the payment of the
                    Change of Control Payment, all Notes accepted for payment
                    pursuant to the Change of Control Offer shall cease to
                    accrue interest on and after the Change of Control Payment
                    Date;

               (5)  that Holders electing to have any Notes purchased pursuant
                    to a Change of Control Offer shall be required to surrender
                    the Notes, with the form entitled "Option of Holder to Elect
                    Purchase" on the reverse of the Notes completed, to the
                    Paying Agent at the address specified in such notice prior
                    to the close of business on the fifth Business Day preceding
                    the Change of Control Payment Date;

                                       32
<Page>

               (6)  that Holders will be entitled to withdraw their election if
                    the Paying Agent receives, not later than the close of
                    business on the second Business Day preceding the Change of
                    Control Payment Date, facsimile transmission or letter
                    setting forth the name of the Holder, the principal amount
                    of Notes delivered for purchase, and a statement that such
                    Holder is withdrawing its election to have such Notes
                    purchased; and

               (7)  that Holders whose Notes are being purchased only in part
                    will be issued new Notes equal in principal amount to the
                    unpurchased portion of the Notes surrendered, which
                    unpurchased portion must be equal to $1,000 in principal
                    amount or an integral multiple thereof.

               The Company shall comply with the requirements of Rule 14e-1
under the Exchange Act and any other securities laws and regulations thereunder,
to the extent such laws and regulations are applicable to the repurchase of the
Notes in connection with a Change of Control. To the extent that the provisions
of any securities laws or regulations conflict with this Section 4.18, the
Company shall comply with the applicable securities laws and regulations and
shall not be deemed to have breached its obligations under the Change of Control
provisions of the Indenture or the First Supplemental Indenture by virtue of
such conflict.

               (b)  On the Change of Control Payment Date, the Company shall, to
the extent lawful:

               (1)  accept for payment Notes or portions thereof tendered
                    pursuant to the Change of Control Offer;

               (2)  deposit with the Paying Agent an amount equal to the Change
                    of Control Payment in respect of all Notes or portions
                    thereof so tendered; and

               (3)  deliver or cause to be delivered to the Trustee the Notes so
                    accepted together with an Officers' Certificate stating the
                    Notes or portions thereof tendered to the Company.

               The Paying Agent shall promptly mail to each Holder of Notes so
accepted the Change of Control Payment for such Notes, and the Trustee shall
promptly authenticate and mail to each Holder a new Note equal in principal
amount to any unpurchased portion of the Notes surrendered, if any; provided
that each such new Note shall be in a principal amount of $1,000 or an integral
multiple thereof. Prior to complying with the provisions of this Section 4.18,
but in any event within 90 calendar days following a Change of Control, the
Company shall either repay all outstanding Senior Debt or obtain the requisite
consents, if any, under all agreements governing outstanding Senior Debt to
permit the repurchase of Notes required by this Section 4.18. The Company shall
publicly announce in The Wall Street Journal, or if no longer published, a
national newspaper of general circulation, the results of the Change of Control
Offer on or as soon as practicable after the Change of Control Payment Date.

               The Company shall not be required to make a Change of Control
Offer upon a Change of Control if a third party makes the Change of Control
Offer in the manner, at the times and otherwise in compliance with the
requirements set forth in this Section 4.18 applicable to a Change of Control
Offer made by the Company and purchases all Notes properly tendered and not
withdrawn under the Change of Control Offer.

                                       33
<Page>

Section 2.7. SUBSIDIARY GUARANTEES.

               With respect to the Notes issued under this Supplemental
Indenture, Article XII of the Indenture shall apply, and the Notes shall
constitute a Series to be guaranteed by the Guarantors pursuant to Article XII
of the Indenture.

Section 2.8. LEGAL DEFEASANCE AND COVENANT DEFEASANCE.

               With respect to the Notes issued under this Supplemental
Indenture, Article VIII of the Indenture shall apply, and the Company shall have
the option to effect Legal Defeasance or Covenant Defeasance pursuant to Article
VIII of the Indenture. In connection with any Covenant Defeasance, the Company
shall be released from its obligations under the covenants specified in Section
5.1 of the Indenture and Section 2.6 of this First Supplemental Indenture.

Section 2.9. SUBORDINATION

               With respect to the Notes issued under this Supplemental
Indenture, Article XIII of the Indenture shall apply, and the Notes shall be
subject to subordination pursuant to Article XIII of the Indenture.

                                   ARTICLE 3.

                                  MISCELLANEOUS

Section 3.1. EFFECT OF HEADINGS.

               The Article and Section headings herein are for convenience only
and shall not affect the construction hereof.

Section 3.2. SUCCESSORS AND ASSIGNS.

               All covenants and agreements in this First Supplemental Indenture
by the Company shall bind its successors and assigns, whether so expressed or
not.

Section 3.3. SEPARABILITY CLAUSE.

               In case any provision in this First Supplemental Indenture or in
the Notes shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

Section 3.4. GOVERNING LAW.

               This First Supplemental Indenture and the Notes created hereby
shall be governed by and construed in accordance with the laws of the State of
New York without giving effect to any conflicts of law provisions (other than
Section 5-1401 of the New York General Obligations Law) that might cause this
First Supplemental Indenture and the Notes to be governed by or construed or
enforced in accordance with the laws of any other jurisdiction.

Section 3.5. FIRST SUPPLEMENT TO SUPERSEDE INDENTURE.

                                       34
<Page>

               The Indenture, as supplemented by the First Supplemental
Indenture, remains in full force and effect as of the date hereof.
Notwithstanding the foregoing, to the extent that any provision of the Indenture
shall conflict with any provision of this First Supplemental Indenture, the
terms of this First Supplemental Indenture shall be deemed controlling and the
conflicting provision of the Indenture shall be null and void to the extent of
such conflict.


           [THE REST OF THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.]

                                       35
<Page>

               IN WITNESS WHEREOF, the parties have caused this First
Supplemental Indenture to be duly executed, and attested, all as of the date and
year first written above.

                              IRON MOUNTAIN INCORPORATED


                              By: /s/ C. Richard Reese
                                  --------------------------------
                              Name:  C. Richard Reese
                              Title: Chairman and Chief Executive Officer

                              GUARANTORS

                              IRON MOUNTAIN INFORMATION
                                MANAGEMENT, INC.
                              COMAC, INC.,
                              DSI TECHNOLOGY ESCROW SERVICES, INC.,
                              IRON MOUNTAIN GLOBAL, INC., and
                              MOUNTAIN REAL ESTATE ASSETS, INC.


                              By: /s/ C. Richard Reese
                                 ---------------------------------
                              Name:  C. Richard Reese
                              Title: Sole Director

                              ARCUS DATA SECURITY LLC and
                              IRON MOUNTAIN SECURE SHREDDING LLC

                              By: IRON MOUNTAIN INFORMATION
                              MANAGEMENT, INC., its Sole Member


                              By:/s/ C. Richard Reese
                                 ---------------------------------
                              Name:  C. Richard Reese
                              Title: Sole Director


                  [First Supplemental Indenture Signature Page]

<page>

                              IRON MOUNTAIN GLOBAL, LLC

                              By:  IRON MOUNTAIN GLOBAL, INC., its Sole
                              Member


                              By: /s/ C. Richard Reese
                                  -------------------------
                              Name:  C. Richard Reese
                              Title: Sole Director

                              IRON MOUNTAIN BUSINESS TRUST #1

                              By: /s/ Richard Reese
                                 --------------------------
                              Name:  C. Richard Reese
                              Title: Trustee

                              By: /s/ John F. Kenny, Jr.
                                  -------------------------
                              Name:  John F. Kenny, Jr.
                              Title: Trustee

                              By: /s/ Garry B. Watze
                                  -------------------------
                              Name:  Garry B. Watze
                              Title: Trustee


                  [First Supplemental Indenture Signature Page]

<page>

                              TRUSTEE

                              THE BANK OF NEW YORK, as Trustee


                              By: /s/ Kisha Holder
                                  --------------------------------
                              Name:  Kisha A. Holder
                              Title: Assistant Treasurer


                  [First Supplemental Indenture Signature Page]

<page>

                                                                   EXHIBIT F

                                                                       Exhibit A

--------------------------------------------------------------------------------


--------------------------------------------------------------------------------

                                 [Face of Note]
                    7 3/4% Senior Subordinated Notes due 2015

CUSIP No. ___________________                                  $ _______________

                           IRON MOUNTAIN INCORPORATED

promises to pay to _______________ or registered assigns, the principal sum of
___________________ Dollars on January 15, 2015.

          Interest Payment Dates:  January 15 and July 15

          Record Dates:  January 2 and July 1

          Dated:  December 30, 2002

                                          IRON MOUNTAIN INCORPORATED

                                          By:
                                              ----------------------------------
                                          Name:
                                          Title:

                                          By:
                                              ----------------------------------
                                          Name:
                                          Title

                                     (SEAL)

This is one of the Notes
referred to in the within-
mentioned Indenture:

THE BANK OF NEW YORK,
as Trustee

By:
    ---------------------------------
          Authorized Signature

                                       F-1
<page>

                                 [Back of Note]
                    7 3/4% Senior Subordinated Notes due 2015

               [INSERT IN GLOBAL NOTES] [This Security is a Global Security
within the meaning of the Indenture hereinafter referred to and is registered in
the name of the Depository or a nominee of the Depository. This Security is
exchangeable for Securities registered in the name of a Person other than the
Depository or its nominee only in the limited circumstances described in the
Indenture, and may not be transferred except as a whole by the Depository to a
nominee of the Depository, by a nominee of the Depository to the Depository or
another nominee of the Depository or by the Depository or any such nominee to a
successor Depository or a nominee of such a successor Depository.]

               Unless and until it is exchanged in whole or in part for Notes in
definitive form, this Note may not be transferred except as a whole by the
Depository to a nominee of the Depository or by a nominee of the Depository to
the Depository or another nominee of the Depository or by the Depository or any
such nominee to a successor Depository or a nominee of such successor
Depository. Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) ("DTC"),
to the issuer or its agent for registration of transfer, exchange or payment,
and any certificate issued is registered in the name of Cede & Co. or such other
name as may be requested by an authorized representative of DTC (and any payment
is made to Cede & Co. or such other entity as may be requested by an authorized
representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner
hereof, Cede & Co., has an interest herein.

               Capitalized terms used herein shall have the meanings assigned to
them in the Indenture referred to below unless otherwise indicated.

               1.   INTEREST. Iron Mountain Incorporated, a Pennsylvania
corporation (the "COMPANY") promises to pay interest on the principal amount of
this Note at 7 3/4% per annum from December 30, 2002 until January 15, 2015. The
Company shall pay interest, semi-annually in arrears on January 15 and July 15
of each year, or if any such day is not a Business Day, on the next succeeding
Business Day (each an "INTEREST PAYMENT DATE"). Interest on the Notes will
accrue from the most recent date to which interest has been paid or, if no
interest has been paid, from the date of issuance; PROVIDED that if there is no
existing Default in the payment of interest, and if this Note is authenticated
between a record date referred to on the face hereof and the next succeeding
Interest Payment Date, interest shall accrue from such next succeeding Interest
Payment Date; PROVIDED, FURTHER, that the first Interest Payment Date shall be
July 15, 2003. The Company shall pay interest (including post-petition interest
to the extent allowed in any proceeding under any Bankruptcy Law) on overdue
principal from time to time on demand at a rate equal to the per annum rate on
the Notes then in effect; it shall pay interest (including post-petition
interest to the extent allowed in any proceeding under any Bankruptcy Law) on
overdue installments of interest (without regard to any applicable grace
periods) from time to time on demand at the same rate to the extent lawful.
Interest will be computed on the basis of a 360-day year of twelve 30-day
months.

               2.   METHOD OF PAYMENT. The Company will pay principal, premium,
if any, and interest on the Notes in money of the United States that at the time
of payment is legal tender for payment of public and private debts. The Company,
however, may pay principal, premium, if any, and interest by check payable in
such money. It may mail an interest check to a Holder's registered address.

               3.   PAYING AGENT, REGISTRAR AND SERVICE AGENT. Initially, The
Bank of New York, the Trustee under the Indenture, will act as Paying Agent,
Registrar and Service Agent. The Notes

                                       F-2
<Page>

may be presented for registration of transfer and exchange at the offices of the
Registrar. The Company may change any Paying Agent, Service Agent or Registrar
without notice to any Holder. The Company or any of its Subsidiaries may act in
any such capacity.

               4.   INDENTURE. The Company issued the Notes under an Indenture
dated as of December 30, 2002 (the "BASE INDENTURE") as supplemented by a First
Supplemental Indenture dated as of December 30, 2002 (the "SUPPLEMENTAL
INDENTURE" and, together with the Base Indenture, the "INDENTURE") among the
Company, the Guarantors and the Trustee. The terms of the Notes include those
stated in the Indenture and those made part of the Indenture by reference to the
Trust Indenture Act of 1939, as amended (15 U.S. Code Sections 77aaa-77bbbb).
The Notes are subject to all such terms, and Holders are referred to the
Indenture and such Act for a statement of such terms. To the extent any
provision of this Note conflicts with the express provisions of the Indenture,
the provisions of the Indenture shall govern and be controlling. The Notes
issued under the Indenture are subordinated unsecured obligations of the Company
limited to $100,000,000 in aggregate principal amount.

               5.   OPTIONAL REDEMPTION.

               Prior to January 15, 2008, the Notes shall be subject to
redemption at any time at the option of the Company, in whole or in part, upon
not less than 30 nor more than 60 days' notice, at the Make-Whole Price, plus
accrued and unpaid interest, to but excluding the applicable redemption date. On
and after January 15, 2008, the Notes will be subject to redemption at any time
at the option of the Company, in whole or in part, upon not less than 30 nor
more than 60 days' notice, at the redemption price (expressed as percentages of
principal amount) set forth below, plus accrued and unpaid interest, to but
excluding the applicable redemption date, if redeemed during the twelve-month
period beginning on January 15 of the years indicated below:

<Table>
<Caption>
               YEAR                                          PERCENTAGE
               ----                                          ----------
               <S>                                             <C>
               2008......................................      103.875%
               2009......................................      102.583%
               2010......................................      101.292%
               2011 and thereafter.......................      100.000%
</Table>

               Notwithstanding the foregoing, at any time prior to January 15,
2006, the Company may redeem up to 35% of the initial principal amount of the
Notes originally issued with the net proceeds of one or more Qualified Equity
Offerings at a redemption price equal to 107.750% of the principal amount of
such Notes, plus accrued and unpaid interest to but excluding the redemption
date; provided, that at least 65% of the principal amount of Notes originally
issued remains outstanding immediately after the occurrence of any such
redemption and that such redemption occurs within 60 days following the closing
of any such Qualified Equity Offering.

               6.   NOTICE OF REDEMPTION.

               Notice of redemption will be mailed at least 30 days but not more
than 60 days before the redemption date to each Holder of the Notes to be
redeemed at such Holder's address of record. The Notes in denominations larger
than $1,000 may be redeemed in part but only in integral multiples of $1,000,
unless all the Notes held by a Holder are to be redeemed. In the event of a
redemption of less than all of the Notes, the Notes will be chosen for
redemption by the Trustee in accordance with the Indenture. On and after the
redemption date, interest ceases to accrue on the Notes or portions of them
called for redemption.

                                       F-3
<Page>

               If this Note is redeemed subsequent to a Record Date with respect
to any Interest Payment Date specified above and on or prior to such Interest
Payment Date, then any accrued interest will be paid to the Person in whose name
this Note is registered at the close of business on such Record Date.

               7.   MANDATORY REDEMPTION. Except as set forth in paragraph 8
below, the Company shall not be required to repurchase or to make mandatory
redemption payments with respect to the Notes. There are no sinking fund
payments with respect to the Notes.

               8.   REPURCHASE AT OPTION OF HOLDER. This Note is subject to
purchase at the option of the Holder upon the circumstances set forth in
Sections 3.9, 4.17 and 4.18 of the Indenture.

               9.   SUBORDINATION. The payment of the principal of, interest on
or any other amounts due on the Notes is subordinated in right of payment to all
existing and future Senior Debt of the Company, as described in the Indenture.
Each Holder, by accepting a Note, agrees to such subordination and authorizes
and directs the Trustee on its behalf to take such action as may be necessary or
appropriate to effectuate the subordination so provided and appoints the Trustee
as its attorney-in-fact for such purpose.

               10.  DENOMINATIONS, TRANSFER, EXCHANGE. The Notes are in
registered form without coupons in minimum denominations of $1,000 and integral
multiples of $1,000 in excess thereof. The transfer of Notes may be registered
and Notes may be exchanged as provided in the Indenture. The Registrar and the
Trustee may require a Holder, among other things, to furnish appropriate
endorsements and transfer documents and the Company may require a Holder to pay
any taxes and fees required by law or permitted by the Indenture. The Company
need not exchange or register the transfer of any Note or portion of a Note
selected for redemption, except for the unredeemed portion of any Note being
redeemed in part. Also, the Company need not exchange or register the transfer
of any Notes for a period of 15 days before a selection of Notes to be redeemed
or during the period between a record date and the corresponding Interest
Payment Date.

               11.  PERSONS DEEMED OWNERS. The registered Holder of a Note may
be treated as its owner for all purposes.

               12.  AMENDMENT, SUPPLEMENT AND WAIVER. Subject to certain
exceptions, the Indenture with respect to the Notes or the Notes may be amended
or supplemented with the written consent of the Holders of a majority in
principal amount of the Notes and any existing default or compliance with any
provision of the Indenture with respect to the Notes or the Notes may be waived
with the consent of the Holders of a majority in principal amount of the Notes
(including, in each case, Additional Notes, if any). Without the consent of any
Holder of the Notes, the Indenture with respect to the Notes or the Notes may be
amended or supplemented to, in addition to other events more fully described in
the Indenture, cure any ambiguity, defect or inconsistency, provide for
uncertificated Notes in addition to or in place of certificated Notes, provide
for the assumption of the Company's obligations to Holders of the Notes in the
case of a merger or consolidation, make any change that would provide any
additional rights or benefits to the Holders of the Notes or that does not
adversely affect the legal rights under the Indenture of any such Holder, or
comply with requirements of the SEC in order to effect or maintain the
qualification of the Indenture under the TIA.

               13.  DEFAULTS AND REMEDIES. An Event of Default with respect to
the Notes occurs upon the occurrence of any of the following events: the default
for 30 days in the payment when due of interest on the Notes (whether or not
prohibited by the subordination provisions of the Indenture); the default in
payment when due of the principal of or premium, if any, on the Notes (whether
or not

                                       F-4
<Page>

prohibited by the subordination provisions of the Indenture); the failure by the
Company to comply with Section 4.18 of the Indenture; the failure by the Company
or any Guarantor for 60 days after written notice from the Trustee or Holders of
not less than 25% of the aggregate principal amount of the Notes (including
Additional Notes, if any) outstanding to comply with any of its other agreements
in the Indenture, Notes or the Subsidiary Guarantees; the default under any
mortgage, indenture or instrument under which there may be issued or by which
there may be secured or evidenced any Indebtedness for money borrowed by the
Company or any of its Restricted Subsidiaries (or the payment of which is
guaranteed by the Company or any of its Restricted Subsidiaries) whether such
Indebtedness or guarantee exists on the date of the Indenture or is created
thereafter, if: (i) such default results in the acceleration of such
Indebtedness prior to its express maturity or shall constitute a default in the
payment of such Indebtedness at final maturity of such Indebtedness and (ii) the
principal amount of any such Indebtedness that has been accelerated or not paid
at maturity, when added to the aggregate principal amount of all other such
Indebtedness that has been accelerated or not paid at maturity, exceeds $10.0
million; the failure by the Company or any of its Restricted Subsidiaries to pay
final judgments aggregating in excess of $10.0 million, which judgments remain
unpaid, undischarged or unstayed for a period of 60 days; certain events of
bankruptcy or insolvency with respect to the Company or any of its Restricted
Subsidiaries that is a Significant Subsidiary; or except as permitted by the
Indenture or the Subsidiary Guarantees, any Subsidiary Guarantee issued by a
Restricted Subsidiary shall be held in any judicial proceeding to be
unenforceable or invalid or shall cease for any reason to be in full force and
effect, or any Restricted Subsidiary or any Person acting on behalf of any
Restricted Subsidiary shall deny or disaffirm in writing its obligations under
its Subsidiary Guarantee.

               If any Event of Default occurs and is continuing, the Trustee or
the Holders of at least 25% in principal amount of the then outstanding Notes
(including Additional Notes, if any) may declare all the Notes to be due and
payable immediately; provided, however, that if any Obligation with respect to
Senior Bank Debt is outstanding pursuant to the Credit Agreement upon a
declaration of acceleration of the Notes, the principal, premium, if any, and
interest on the Notes will not be payable until the earlier of: (1)the day which
is five business days after written notice of acceleration is received by the
Company and the Credit Agent or (2) the date of acceleration of the Indebtedness
under the Credit Agreement. Notwithstanding the foregoing, in the case of an
Event of Default arising from certain events of bankruptcy or insolvency with
respect to the Company or any Restricted Subsidiary that is a Significant
Subsidiary, the principal of, and premium, if any, and any accrued and unpaid
interest on all outstanding Notes will become due and payable without further
action or notice. In the event of a declaration of acceleration of the Notes
because an Event of Default has occurred and is continuing as a result of the
acceleration of any Indebtedness described in Section 6.1(e) of the Indenture,
the declaration of acceleration of the Notes shall be automatically annulled if
the holders of any Indebtedness described in such section have rescinded the
declaration of acceleration in respect of such Indebtedness within 30 days from
the date of such declaration and if: (1) the annulment of the acceleration of
the Notes would not conflict with any judgment or decree of a competent
jurisdiction and (2) all existing Events of Default, except non-payment of
principal or interest on the Notes that became due solely because of the
acceleration of the Notes, have been cured or waived.

               Subject to certain limitations, Holders of a majority in
principal amount of the then outstanding Notes may direct the Trustee in its
exercise of any trust or power. The Trustee may withhold from Holders of the
Notes notice of any continuing Default or Event of Default (except a Default or
Event of Default relating to the payment of principal or interest) if it
determines that withholding notice is in their interest. The Company is required
to deliver to the Trustee annually a statement regarding compliance with the
Indenture, and the Company is required, upon becoming aware of any Default or
Event of Default, to deliver to the Trustee a statement specifying such Default
or Event of Default and what action the Company is taking or proposes to take
thereto.

                                       F-5
<Page>

               14.  SUBSIDIARY GUARANTEES. Payment of principal of, premium, if
any, and interest (including interest on overdue principal, if any, and
interest, if lawful) on the Notes is guaranteed on an unsecured, senior
subordinated basis by the Guarantors pursuant to Article XII of the Indenture.

               15.  TRUSTEE DEALINGS WITH COMPANY. The Trustee, in its
individual or any other capacity, may make loans to, accept deposits from, and
perform services for the Company or its Affiliates, and may otherwise deal with
the Company or its Affiliates, as if it were not the Trustee.

               16.  NO RECOURSE AGAINST OTHERS. No past, present or future
director, officer, employee, incorporator or stockholder, as such, of the
Company or any Guarantor shall have any liability for any obligations of the
Company or any Guarantor under the Notes, the Subsidiary Guarantees or the
Indenture or for any claim based on, in respect of or by reason of such
obligations or their creation. Each Holder by accepting a Note and the related
Subsidiary Guarantees waives and releases all such liability. The waiver and
release are part of the consideration for the issuance of the Notes.

               17.  AUTHENTICATION. This Note shall not be valid until
authenticated by the manual signature of the Trustee or an authenticating agent.

               18.  ABBREVIATIONS. Customary abbreviations may be used in the
name of a Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT
(= tenants by the entireties), JT TEN (= joint tenants with right of
survivorship and not as tenants in common), CUST (= Custodian), and U/G/M/A (=
Uniform Gifts to Minors Act).

               19.  CUSIP NUMBERS. Pursuant to a recommendation promulgated by
the Committee on Uniform Security Identification Procedures, the Company has
caused CUSIP numbers to be printed on the Notes and the Trustee may use CUSIP
numbers in notices of redemption as a convenience to Holders. No representation
is made as to the accuracy of such numbers either as printed on the Notes or as
contained in any notice of redemption and reliance may be placed only on the
other identification numbers placed thereon.

               The Company shall furnish to any Holder upon written request and
without charge a copy of the Indenture. Requests may be made to:

                    Iron Mountain Incorporated
                    745 Atlantic Avenue
                    Boston, Massachusetts 02111
                    Attention:  Chief Financial Officer

                                       F-6
<Page>

                                 ASSIGNMENT FORM

     To assign this Note, fill in the form below:  (I) or (we) assign and
     transfer this Note to

________________________________________________________________________________
                  (Insert assignee's soc. sec. or tax I.D. no.)


________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________
              (Print or type assignee's name, address and zip code)

and irrevocably appoint ________________________________________________________
to transfer this Note on the books of the Company. The agent may substitute
another to act for him.

________________________________________________________________________________

Date:
     --------------

Your Signature:
               -----------------------------------------------------------------
(Sign exactly as your name appears on the face of this Note)

                                       F-7
<Page>

                       OPTION OF HOLDER TO ELECT PURCHASE

               If you want to elect to have this Note purchased by the Company
pursuant to Section 4.17 or 4.18 of the Indenture, check the box below:

                     / / Section 4.17

                     / / Section 4.18

               If you want to elect to have only part of the Note purchased by
the Company pursuant to Section 4.17 of the Supplemental Indenture, state the
amount you elect to have purchased: $________

Date:                           Your Signature:
     ------------------                        ---------------------------------
                                (Sign exactly as your name appears on the Note)

                                Tax Identification No.: ________________________

                                       F-8
<Page>

                        SCHEDULE OF EXCHANGES OF NOTES*

      The following exchanges of a part of this Global Note for other Notes
have been made:

<Table>
                                                          Principal Amount of    Signature of
                       Amount of          Amount of         this Global Note   authorized office
                      decrease in        decrease in         following such      of Trustee or
                   Principal Amount    Principal Amount       decrease (or       Service Agent
Date of Exchange  of this Global Note of this Global Note      increase
----------------  ------------------- ------------------- -------------------  -----------------
<S>               <C>                 <C>                 <C>                   <C>


</Table>

----------
*This schedule should be included only if the Note is issued in global form.

                                       F-9
<Page>

                                    EXHIBIT B

       FORM OF SUPPLEMENTAL INDENTURE TO BE DELIVERED BY FUTURE GUARANTORS

               SUPPLEMENTAL INDENTURE (this "SUPPLEMENTAL INDENTURE"), dated as
of ________________, _____, among _______________ (the "GUARANTEEING
SUBSIDIARY"), a subsidiary of Iron Mountain Incorporated (or its successor), a
Pennsylvania corporation (the "COMPANY"), the Company, and The Bank of New York,
a New York banking corporation, as trustee under the Indenture referred to below
(the "TRUSTEE").

                               W I T N E S S E T H

               WHEREAS, the Company has heretofore executed and delivered to the
Trustee an indenture, dated as of December 30, 2002, as supplemented by the
First Supplemental Indenture, dated as of December 30, 2002 (the indenture, as
so supplemented, the "INDENTURE") providing for the issuance of an aggregate
principal amount of up to $100,000,000 of 7 3/4% Senior Subordinated Notes due
2015 (the "NOTES");

               WHEREAS, the Indenture provides that under certain circumstances
the Guaranteeing Subsidiary shall execute and deliver to the Trustee a
supplemental indenture pursuant to which the Guaranteeing Subsidiary shall
unconditionally guarantee all of the Company's obligations under the Notes and
the Indenture on the terms and conditions set forth herein (the "NOTE
GUARANTEE"); and

               WHEREAS, pursuant to Section 9.1 of the Indenture, the Trustee is
authorized to execute and deliver this Supplemental Indenture.

               NOW THEREFORE, in consideration of the foregoing and for other
good and valuable consideration, the receipt of which is hereby acknowledged,
the Guaranteeing Subsidiary and the Trustee mutually covenant and agree for the
equal and ratable benefit of the Holders of the Notes as follows:

               1.   CAPITALIZED TERMS. Capitalized terms used herein without
definition shall have the meanings assigned to them in the Indenture.

               2.   AGREEMENT TO GUARANTEE. The Guaranteeing Subsidiary hereby
agrees that its obligations to the Holder and the Trustee pursuant to this
Subsidiary Guarantee shall be as expressly set forth in Article XII of the
Indenture and in such other provisions of the Indenture as are applicable to the
Guarantors (including, without limitation, Article XIII of the Indenture), and
reference is made to the Indenture for the precise terms of this Supplemental
Indenture. The terms of Article XII of the Indenture and such other provisions
of the Indenture (including, without limitation, Article XIII of the Indenture)
as are applicable to the Guarantors are incorporated herein by reference.

               3.   EXECUTION AND DELIVERY OF SUBSIDIARY GUARANTEES.

                    (a)   If an Officer whose signature is on this Supplemental
Indenture no longer holds that office at the time the Trustee authenticates the
Note, the Subsidiary Guarantee shall be valid nevertheless.

                    (b)   The delivery of any Note by the Trustee, after the
authentication thereof under the Indenture, shall constitute due delivery of the
Subsidiary Guarantee set forth in this Supplemental Indenture on behalf of the
Guaranteeing Subsidiary.

                                      F-10
<Page>

               4.   NO RECOURSE AGAINST OTHERS. No past, present or future
director, officer, employee, incorporator or stockholder of the Guaranteeing
Subsidiary, as such, shall have any liability for any obligations of the Company
or any Guarantor (including the Guaranteeing Subsidiary) under the Notes, any
Subsidiary Guarantee, the Indenture or this Supplemental Indenture or for any
claim based on, in respect of, or by reason of, such obligations or their
creation. Each Holder of the Notes by accepting a Note waives and releases all
such liability. The waiver and release are part of the consideration for
issuance of the Notes.

               5.   NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW
YORK SHALL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE BUT
WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT
THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED
THEREBY.

               6.   COUNTERPARTS. The parties may sign any number of copies of
this Supplemental Indenture. Each signed copy shall be an original, but all of
them together represent the same agreement.

               7.   EFFECT OF HEADINGS. The Section headings herein are for
convenience only and shall not affect the construction hereof.

               8.   THE TRUSTEE. The Trustee shall not be responsible in any
manner whatsoever for or in respect of the validity or sufficiency of this
Supplemental Indenture or for or in respect of the recitals contained herein,
all of which recitals are made solely by the Guaranteeing Subsidiary and the
Company.

                                      F-11
<Page>

               IN WITNESS WHEREOF, the parties hereto have caused this
Supplemental Indenture to be duly executed and attested, all as of the date
first above written.

               Dated:  _______________, 20___

                                             [GUARANTEEING SUBSIDIARY]

                                             By:
                                                  ------------------------------
                                             Name:
                                             Title:

                                             [COMPANY]

                                             By:
                                                  ------------------------------
                                             Name:
                                             Title:

                                             [TRUSTEE],
                                              as Trustee

                                             By:
                                                  ------------------------------
                                                  Authorized Signatory

                                      F-12