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                                                                   Exhibit 10.10

                             AC SAFETY HOLDING CORP.
                         2004 DEFERRED COMPENSATION PLAN

                            Dated as of April 7, 2004

         The AC Safety Holding Corp. 2004 Deferred Compensation Plan (the
"Plan") has been adopted by AC Safety Holding Corp., a corporation organized
under the laws of the state of Delaware, effective as of the Effective Date (as
hereinafter defined), for the benefit of its eligible employees. The Plan is a
nonqualified deferred compensation plan pursuant to which the employees of the
Company (as hereinafter defined) who are selected for participation in the Plan
may defer compensation. The Plan is maintained primarily for the purpose of
providing deferred compensation for a select group of management or highly
compensated employees, within the meaning of Sections 201(2), 301(a)(3) and
401(a)(1) of the Employee Retirement Income Security Act of 1974, as amended.

                                    ARTICLE I

                                   DEFINITIONS

         The following words and phrases used in this Plan shall have the
respective meanings set forth below unless the context clearly indicates to the
contrary. Wherever appropriate herein, words used in the singular shall be
considered to include the plural, words used in the plural shall be considered
to include the singular, and the masculine gender shall be deemed to include the
feminine gender.

         Section 1.1 "Administrator" shall mean the Company acting through the
Board or any Person to whom it delegates its authority pursuant to Article V.

         Section 1.2 "Board" shall mean the Board of Directors of the Company.

         Section 1.3 "Bonus" shall mean that portion of the consideration
received by a Participant on the Closing Date as a "Transaction Bonus" that is
credited to such Participant's Deferred Compensation Account in accordance with
Section 2.2 of the Plan, pursuant to and determined in accordance with the
Participant's Subscription Agreement.

         Section 1.4 "Closing Date" shall mean the date on which the Proposed
Merger is consummated.

         Section 1.5 "Come Along Transaction" shall have the meaning given to
such term in the Stockholders' Agreement.

         Section 1.6 "Common Stock" shall mean shares of Company's common stock,
par value $0.01 per share.

         Section 1.7 "Company" shall mean AC Safety Holding Corp., a Delaware
corporation.

         Section 1.8 "Deferred Common Stock Unit" shall mean the right of a
Participant to receive one share of Common Stock as of the Distribution Date in
accordance with Article IV.



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         Section 1.9 "Deferred Compensation Account" of a Participant shall mean
the bookkeeping account established on behalf of the Participant in accordance
with Section 3.1.

         Section 1.10 "Deferred Preferred Stock Unit" shall mean the right of a
Participant to receive one share of Preferred Stock as of the Distribution Date
in accordance with Article IV.

         Section 1.11 "Distribution Date" shall mean the date on which the event
described in Section 4.1 shall occur.

         Section 1.12 "Effective Date" means the effective date of the Plan
which shall be the Closing Date.

         Section 1.13 "Exit Event" shall be deemed to have occurred (i) upon the
expiration of the period of time following the consummation of an Initial
Offering, as determined by the managing underwriters, during which the Bear
Group Holders (as such term is defined in the Stockholders' Agreement) or any
other stockholders of the Company are contractually prohibited from selling,
making any short sale of, granting any option for the purchase of, or otherwise
disposing of any Common Stock or Preferred Stock, or securities convertible into
shares of Common Stock or Preferred Stock, (ii) upon consummation of a
Realization Event (as defined in the Company's 2004 Stock Incentive Plan) or
(iii) upon any change of control (or similar event, however denominated) with
respect to the Company under and as defined in any indenture or agreement to
which the Company or any of its subsidiaries is a party with respect to
indebtedness for borrowed money in the excess of the aggregate principal amount
of $100,000,000.

         Section 1.14 "Fund" shall have the meaning set forth in Section 3.4.

         Section 1.15 "Initial Offering" shall mean the initial offering of
Common Stock or Preferred Stock or equity securities of any Person that owns in
excess of 75% of the outstanding voting securities of the Company pursuant to
(i) an offering registered under the Securities Act or (ii) an offering
consummated pursuant to Rule 144A under the Securities Act.

         Section 1.16 "Merger Agreement" shall mean the Agreement and Plan of
Merger dated as of March 10, 2004, by and among the Company, AC Safety
Acquisition Corp., a Delaware corporation, and Aearo Corporation, a Delaware
corporation, as it may be amended, supplemented or restated from time to time.

         Section 1.17 "Participant" shall mean any person included in the Plan
as provided in Article II.

         Section 1.18 "Person" shall be construed broadly and shall include,
without limitation, an individual, a partnership, a corporation, an association,
a joint stock company, a limited liability company, a trust, a joint venture, an
unincorporated organization and a governmental entity or any department, agency
or political subdivision thereof.

         Section 1.19 "Plan" shall mean the AC Safety Holding Corp. 2004
Deferred Compensation Plan, as set forth in this document and as it may
hereafter be amended from time to time.



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         Section 1.20 "Preferred Stock" shall mean shares of the Company's
Series A Preferred Stock, par value $0.01 per share.

         Section 1.21 "Proposed Merger" shall mean that certain proposed merger
of AC Safety Acquisition Corp. into Aearo Corporation.

         Section 1.22 "Public Sale" shall have the meaning given to such term in
the Stockholders' Agreement.

         Section 1.23 "Stockholders' Agreement" shall mean the Stockholders'
Agreement dated as of the date hereof, by and among the Company and the holders
party thereto, as it may be amended, supplemented or restated from time to time.

         Section 1.24 "Subsidiary" shall mean with respect to any Person, any
other Person that, directly or indirectly through one or more intermediaries
Controls, is Controlled by, or is under common Control with, such Person. The
term "Control" means the possession, directly or indirectly, of the power to
cause or director the management and policies of a Person, whether through the
ownership of voting securities, by contract or otherwise.

         Section 1.25 "Subscription Agreement" with respect to any Person shall
mean any Subscription Agreement (however denominated) dated as of the Closing
Date between such Person and the Company that contains a provision expressly
providing for a bonus credit under this Plan in an amount equal to the
Transaction Bonus set forth in such Subscription Agreement.

         Section 1.26 "Tag Along Transaction" shall have the meaning given to
such term in the Stockholders' Agreement.

         Section 1.27 "Termination of Employment" shall mean the time when the
employee-employer relationship between the Participant and the Company or any of
its Subsidiaries is terminated for any reason, with or without cause, including,
but not by way of limitation, a termination by resignation, discharge,
disability, death or retirement, but excluding transfers of such Participant's
employment among and between the Company and any Subsidiary of the Company.

                                   ARTICLE II

                                  PARTICIPATION

         Section 2.1 Participation. Unless otherwise determined by the
Administrator in its sole discretion, each employee of the Company who is a
party to a Subscription Agreement and is actively employed by the Company or any
of its Subsidiaries as of the Closing Date shall be eligible to participate in
the Plan.

         Section 2.2 Deferred Compensation Account. In accordance with the terms
set forth in the Subscription Agreement, on the Closing Date, each Participant's
Deferred Compensation Account shall be credited with such Participant's Bonus in
such amount as is set forth in such Participant's Subscription Agreement.



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                                  ARTICLE III

                                    ACCOUNTS

         Section 3.1 Deferred Compensation Accounts.

             (a) The Administrator shall establish and maintain for each
Participant a Deferred Compensation Account to which shall be (i) credited the
amounts determined under Section 3.1(b) and (ii) debited the amount of any
distributions under the Plan.

             (b) As of the Closing Date, each Participant's Deferred
Compensation Account shall be credited with the number of Deferred Common Stock
Units and Deferred Preferred Stock Units set forth in his Subscription
Agreement. Notwithstanding any other provision of this Plan, no amount shall be
credited to any Participant's Deferred Compensation Account prior to the Closing
Date.

         Section 3.2 Designation of Beneficiary. Each Participant shall have the
right to designate, revoke and redesignate beneficiaries hereunder and to direct
payment of the amount or distribution of the items credited to his Deferred
Compensation Account to such beneficiaries upon his death. Designation,
revocation and redesignation of beneficiaries shall be made on such form as
shall be designated by the Administrator and shall be effective upon delivery to
the Administrator.

         Section 3.3 Assignments Prohibited. No part of a Participant's Deferred
Compensation Account shall be liable for the debts, contracts or engagements of
any Participant, his beneficiaries or successors in interest, or be taken in
execution by levy, attachment or garnishment or by any other legal or equitable
proceeding, nor shall any such person have any rights to alienate, anticipate,
commute, pledge, encumber or assign any benefits or payments hereunder in any
manner whatsoever except to designate a beneficiary as provided herein.

         Section 3.4 Fund. The Administrator may, in its discretion, establish a
fund (the "Fund") to which the Company may contribute cash or other property,
including securities issued by the Company, to provide for the benefit payments
under this Plan; provided, however, that such Fund shall remain a general asset
of the Company subject to the rights of creditors of the Company in the event of
the Company's bankruptcy or insolvency as defined in any such Fund. The Company
shall designate a trustee to hold any such Fund in trust in accordance with the
terms of the applicable trust agreement. The Company's obligations under this
Plan may be satisfied with Fund assets distributed pursuant to the terms of the
trust, and any such distribution shall reduce the Company's obligations under
this Plan.

         Section 3.5 Dividend Equivalents.

             (a) As of the date the Company pays any dividend (other than cash
dividends) on shares of Common Stock or Preferred Stock, each Participant's
Deferred Compensation Account shall be credited with that number of Deferred
Common Stock Units or Deferred Preferred Stock Units, as applicable, equal to
the ratio of (i) the aggregate value of the dividend that would have been
payable on the respective units held by such Participant immediately prior to
such payment date had the shares of Common Stock or Preferred Stock represented
by the respective units been outstanding as of such payment date to (ii) the
fair market value of the shares of Common Stock or Preferred Stock, as
applicable, as such fair market value is determined as of that time in good
faith by the Administrator for purposes of this Plan. Any such determination by
the Administrator in good faith shall be final and binding on all persons.



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             (b) As promptly as practicable following the date the Company pays
any cash dividend on shares of Common Stock or Preferred Stock, the Company
shall pay to each Participant an amount in cash equal to the product of (i) the
number of Deferred Common Stock Units or Deferred Preferred Stock Units, as
applicable, in such Participant's Deferred Compensation Account at the time of
the record date for such dividend multiplied by (ii) the per share cash amount
of such dividend with respect to shares of Common Stock or Preferred Stock, as
the case may be.

         Section 3.6 Non-Consummation of Proposed Acquisition. Notwithstanding
any other provision of the Plan, in the event that the Proposed Merger Agreement
is terminated in accordance with its terms prior to the Closing Date, the Plan
will terminate as of the effective date of such termination, and in each such
case all Bonuses shall become void and of no effect as of the date of Plan
termination.

                                   ARTICLE IV

                                    BENEFITS

         Section 4.1 Time of Distribution.

             (a) Each Participant's Deferred Compensation Account shall be
distributed to the Participant (or his beneficiaries, as applicable), less any
amounts required to be withheld by applicable law, (i) upon (or as soon as
reasonably practicable following) the earlier to occur following the Closing
Date of (A) the Participant's Termination of Employment and (B) an Exit Event
and (ii) as set forth in Section 4.1(b) and Section 4.1(c) below.

             (b) Notwithstanding anything to the contrary contained herein, if a
Participant has the right to transfer shares of Common Stock and/or Preferred
Stock pursuant to the exercise of tag along rights or registration rights in
accordance with Section 2(a) or Section 4, respectively, of the Stockholders'
Agreement, then the Company will issue and distribute to the Participant the
following:

                           (i) with respect to the Common Stock, a number of
                  shares equal to the maximum number of shares of Common Stock
                  that the Participant is entitled to sell in such Tag Along
                  Transaction or Public Sale (after giving effect to the cutback
                  provisions contained in Section 4(a)(v) or Section 4(b)(ii),
                  as the case may be, of the Stockholders' Agreement), as
                  applicable; and/or

                           (ii) with respect to the Preferred Stock, a number of
                  shares equal to the maximum number of shares of Preferred
                  Stock that the Participant is entitled to sell in such Tag
                  Along Transaction or Public Sale (after giving effect to the
                  cutback provisions contained in Section 4(a)(v) or Section
                  4(b)(ii), as the case may be, of the Stockholders' Agreement),
                  as applicable.



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         In connection with distributions of Common Stock pursuant to this
Section 5.1(b), the Participant's Deferred Compensation Account will be
decreased by (A) decreasing the number of Deferred Common Stock Units held in
such account by the number of shares of Common Stock distributed pursuant to the
immediately preceding sentence and (B) decreasing the number of Deferred
Preferred Stock Units held in such account by the number of shares of Preferred
Stock distributed pursuant to the immediately preceding sentence.

             (c) Notwithstanding anything to the contrary contained herein, if a
Participant has the obligation to transfer shares of Common Stock and/or
Preferred Stock pursuant to the exercise of come along rights in accordance with
Section 2(b) of the Stockholders' Agreement, then the Company will issue and
distribute to the Participant the following:

                           (i) with respect to the Common Stock, a number of
                  shares equal to the maximum number of shares of Common Stock
                  that the Participant is required to sell in such Come Along
                  Transaction; and/or

                           (ii) with respect to the Preferred Stock, a number of
                  shares Preferred Stock equal to the maximum number of shares
                  of Preferred Stock that the Participant is required to sell in
                  such Come Along Transaction.

         In connection with distributions of Common Stock pursuant to this
Section 4.1(c), the Participant's Deferred Compensation Account will be
decreased by (A) decreasing the number of Deferred Common Stock Units held in
such account by the number of shares of Common Stock distributed pursuant to
Section 4.1(c)(i) above and (B) decreasing the number of Deferred Preferred
Stock Units held in such account by the number of shares of Preferred Stock
distributed pursuant Section 4.1(c)(ii) above.

         Section 4.2 Form of Distribution. With respect to Deferred Common Stock
Units, all distributions from the Plan shall be made in the form of whole shares
of Common Stock with fractional shares credited to federal income taxes
withheld. With respect to Deferred Preferred Stock Units, all distributions from
the Plan shall be made in the form of whole shares of Preferred Stock with
fractional shares credited to federal income taxes withheld. Tax withholding
with respect to such distributions shall be pursuant to Section 6.4.

         Section 4.3 Stockholders' Agreement. Notwithstanding anything else
contained herein to the contrary, prior and as a condition to the distribution
of shares of Common Stock or Preferred Stock to a Participant hereunder, such
Participant shall execute an Adoption Agreement (as defined in the Stockholders'
Agreement) pursuant to which such Participant shall become a party to and be
bound by the Stockholders' Agreement and upon such execution such Participant
shall have all the rights and obligations of a Non-Bear Group Holder (as defined
in the Stockholders' Agreement) thereunder.



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                                   ARTICLE V

                            ADMINISTRATIVE PROVISIONS

         Section 5.1 Administrator's Duties and Powers.

             (a) The Board shall conduct the general administration of the Plan
in accordance with the Plan and shall have full discretionary power and
authority to carry out that function. Among its necessary powers and duties, are
the following:

                           (i) To delegate all or part of its function as
                  Administrator to others and to revoke any such delegation.

                           (ii) To determine questions of eligibility of
                  Participants and their entitlement to benefits.

                           (iii) To select and engage attorneys, accountants,
                  actuaries, trustees, appraisers, brokers, consultants,
                  administrators, physicians or other persons to render service
                  or advice with regard to any responsibility the Administrator
                  or the Board has under the Plan, or otherwise, to designate
                  such persons to carry out responsibilities, and (with the
                  Company, the Board and its officers, trustees and employees)
                  to rely upon the advice, opinions or valuations of any such
                  persons, to the extent permitted by law, being fully protected
                  in acting or relying thereon in good faith.

                           (iv) To interpret the Plan for purpose of the
                  administration and application of the Plan, in a manner not
                  inconsistent with the Plan or applicable law and to amend or
                  revoke any such interpretation.

                           (v) To adopt Rules of the Plan that are not
                  inconsistent with the Plan or applicable law and to amend or
                  revoke any such rules.

             (b) Every finding, decision, and determination made by the
Administrator shall, to the full extent permitted by law, be final and binding
upon all parties, except to the extent found by a court of competent
jurisdiction to be unreasonable.

         Section 5.2 Indemnification by the Company; Liability Insurance.

             (a) The Company shall pay or reimburse any of the Company's
officers, directors or employees who administer the Plan for all expenses
incurred by such persons in, and shall indemnify and hold them harmless from,
all claims, liability and costs (including reasonable attorneys' fees) arising
out of the good faith performance of their Plan functions.

             (b) The Company may obtain and provide for any such person, at the
Company's expense, liability insurance against liabilities imposed on him by
law.

         Section 5.3 Limitations Upon Powers. The Plan shall be uniformly and
consistently administered, interpreted and applied with regard to all
Participants in similar circumstances. The Plan shall be administered,
interpreted and applied fairly and equitably in accordance with the specified
purposes of the Plan.



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         Section 5.4 Recordkeeping.

             (a) The Administrator shall maintain suitable records as follows:
(i) records of each Participant's individual Deferred Compensation Accounts,
(ii) records which show the operations of the Plan, and (iii) records of its
deliberations and decisions.

             (b) The Administrator may appoint a secretary to keep the record of
proceedings, to transmit its decisions, instructions, consents or directions to
any interested party, to execute and file, on behalf of the Administrator, such
documents, reports or other matters as may be necessary or appropriate under
applicable law to perform ministerial acts.

             (c) The Administrator shall not be required to maintain any records
or accounts which duplicate any records or accounts maintained by the Company.

         Section 5.5 Service of Process. The Secretary of the Company is hereby
designated as agent of the Plan for the service of legal process.

         Section 5.6 Service in More than One Capacity. Any person or group of
persons may serve in more than one capacity with respect to the Plan.

         Section 5.7 Statement to Participants. The Administrator shall from
time to time in its discretion furnish to each Participant a statement setting
forth the value of his Deferred Compensation Accounts and such other information
as the Administrator shall deem advisable to furnish.

         Section 5.8 Corporate Changes. If the Company at any time (a) increases
or decreases the number of shares of its Common Stock or Preferred Stock then
outstanding proportionately to all holders of such shares, whether by stock
dividend, stock split, consolidation of shares, or (b) otherwise effectuates any
change in the capitalization of the Company (whether by way of merger,
consolidation, reorganization or recapitalization or otherwise), then all
Deferred Common Stock Units and/or Deferred Preferred Stock Units theretofore
credited shall be equitably adjusted with respect to the number of shares of
such Common Stock or Preferred Stock, as applicable, represented thereby (or
exchanged for a right to receive another class or kind of securities which shall
continue to be subject to the terms and provisions of this Plan, mutatis
mutandis) in such manner as shall be determined in good faith by the
Administrator in its sole discretion.

                                   ARTICLE VI

                            MISCELLANEOUS PROVISIONS

         Section 6.1 Amendment of Plan. Except as may otherwise be prohibited by
applicable law, the Plan may be wholly or partially amended by the Administrator
from time to time including retroactive amendments; provided, however, that no
amendment shall decrease the interest any Participant or any other person
entitled to payment under the Plan has in the Participant's Deferred
Compensation Accounts without such Participant's written approval.

         Section 6.2 Errors and Misstatements. In the event of any misstatement
or omission of fact by a Participant to the Administrator or any clerical error
resulting in payment of benefits in an incorrect amount, the Administrator shall
promptly cause the amount of future payments to be corrected upon discovery of
the facts and shall pay the Participant or any other Person entitled to payment
under the Plan any underpayment in cash in a lump sum or to recoup any
overpayment from future payments to the Participant or any other Person entitled
to payment under the Plan in such amounts as the Administrator shall direct or
to proceed against the Participant or any other Person entitled to payment under
the Plan for recovery of any such overpayment.



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         Section 6.3 Governing Law. This Plan shall be construed, administered
and governed in all respects under and by applicable federal laws and, where
state law is applicable, the laws of the State of Delaware.

         Section 6.4 Tax Withholding. During the time a Participant is employed
with the Company or any Subsidiary, the Company (or Subsidiary, as applicable)
shall deduct from such Participant's wages any amounts required to be withheld
by the Company (or Subsidiary, as applicable) with respect to the accrual of a
Participant's benefits hereunder. Further, there shall be deducted from each
payment of a Participant's benefits under the Plan any taxes required to be
withheld by the Company or any Subsidiary in respect of such payment. The
Company (or Subsidiary, as applicable) shall have the right to reduce any
payment by an amount sufficient to pay said taxes. In lieu of a deduction, the
Committee may permit the Participant to pay or reimburse the Company (or
Subsidiary, as applicable) for said taxes.

         Section 6.5 Limitation on Rights of Employees. The Plan is strictly a
voluntary undertaking on the part of the Company and shall not constitute a
contract of employment between the Company (or Subsidiary, as applicable) and
any Participant. Nothing contained in the Plan shall give any Participant the
right to be retained in the service of the Company (or Subsidiary, as
applicable) or to interfere with or restrict the right of the Company (or
Subsidiary, as applicable), which is hereby expressly reserved, to discharge or
retire any Participant, except as provided by law, at any time without notice
and with or without cause. Inclusion under the Plan will not give any
Participant any right or claim to any benefit hereunder except to the extent
such right has specifically become fixed under the terms of the Plan. The
doctrine of substantial performance shall have no application to Participants or
any other persons entitled to payments under the Plan.

         Section 6.6 Payment on Behalf of Minors. In the event any amount
becomes payable under the Plan to a minor or a person who, in the sole judgment
of the Administrator is considered by reason of physical or mental condition to
be unable to give a valid receipt therefor, the Administrator may direct that
such payment be made to any person found by the administrator in its sole
judgment, to have assumed the care of such minor or other person. Any payment
made pursuant to such determination shall constitute a full release and
discharge of the Company, the Board, the Administrator, and their officers,
directors and employees.

         Section 6.7 References. Unless the context clearly indicates to the
contrary, a reference to a statute, regulation or document shall be construed as
referring to any subsequently enacted, adopted or executed statute, regulation
or document.



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         Section 6.8 Termination of the Plan. While the Plan is intended as a
permanent program, the Board shall have the right at any time to declare the
Plan terminated completely as to the Company or as to any division, facility or
other operational unit thereof. In the event of any termination, the
Administrator shall continue to maintain Participants' Deferred Compensation
Accounts (in accordance with the terms of the Plan) and payment of such Deferred
Compensation Accounts shall be made in accordance with Article IV; provided that
the Board may, in its sole discretion, elect to accelerate the distribution date
for Plan benefits to the date of such termination.

         Section 6.9 Effect Upon Other Plans. Except to the extent provided
herein, nothing in this Plan shall be construed to affect the provisions of any
other plan maintained by the Company.

         Section 6.10 Titles. Titles are provided herein for convenience only
and are not to serve as a basis for interpretation or construction of the Plan.

         Section 6.11 Enforcement. In the event the Company or any Participant
institutes litigation to enforce or protect its rights under the Plan, the party
prevailing in any such litigation shall be paid by the non-prevailing party, in
addition to all other relief, all reasonable attorneys' fees, out-of-pocket
costs and disbursements relating to such litigation.

                                      *****






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         IN WITNESS WHEREOF, the Company has caused this instrument to be
executed effective as of the date first above written.

                                           AC SAFETY HOLDING CORP.


                                           By: /s/ Douglas R. Korn
                                               --------------------------------
                                                Name:  Douglas R. Korn
                                                Title:  President