OPTION AND ASSET PURCHASE AGREEMENT

THIS OPTION AND ASSET PURCHASE AGREEMENT(this "Agreement") is entered into and
made effective as of September 16, 1997 (the "Effective Date"), by andamong
MENTOR CORPORATION, a Minnesota corporation, or its assignee (collectively,
"Mentor"), ALCHEMY ENGINEERING, LLC, a California limited liability company
d/b/a SiTech, LLC ("SiTech"), and Richard A. Compton and Del J. Petraitis, the
individual members of SiTech (such individuals, the "Members"). All capitalized
terms used herein and not otherwise defined shall have the meanings ascribed to
them in that certain Exclusive Supply Agreement, of even date herewith, by and
between SiTech and Mentor (the "Supply Agreement").

RECITALS

WHEREAS, the Members are presently the sole members of SiTech;

WHERAS, SiTech has been formed to engage in the business of manufacturing
silicone dispersions, silicone gel and silicone elastomers (the "Business") in a
manufacturing facility located at 6125 Campus Circle, Irving, Texas 75038 (the
"Texas Facility");

WHEREAS, simultaneously herewith, SiTech and Mentor are entering into a Supply
Agreement, whereby SiTech shall manufacture such materials in the Texas Facility
exclusively for Mentor, and Mentor shall purchase such materials exclusively
from SiTech;

WHEREAS, Mentor desires to obtain an option to purchase all of the assets of
SiTech used in the Business, in order to secure a permanent source of supply of
such materials; and

WHERAS, as a condition to execution of the Supply Agreement, SiTech has agreed
and the Members have agreed to cause SiTech, among other things, to grant to
Mentor an exclusive option to purchase all of the assets of SiTech used in the
Business pursuant to the terms and conditions of this Agreement.

NOW, THEREFORE, in consideration of the premises and mutual covenants
hereinafter set forth and other good and valuable consideration, the receipt and
sufficiency of which hereby are acknowledged, the parties agree as follows:

ARTICLE I
OPTION TO PURCHASE

 1.1 Grant of Option. SiTech hereby grants Mentor an irrevocable option (the
"Option") to purchase, as a going concern, all of the right, title and interest
in and to all of the tangible and intangible assets owned by SiTech or to which
it is entitled and belonging to or used or intended to be used in the Business,
of every kind and description and wherever located (collectively, the "Assets"),
as of and with effect from the Closing Date (as defined in Section 1.5(a)
below), upon the terms and conditions set forth in this Agreement. The term of
the Option shall commence on the Effective Date and shall expire upon the
earlier of: (i) the seven (7) year anniversary of the Effective Date; (ii) the
successful closing of the exercise of Mentor's Option hereunder (the "Closing")
or (iii) the early termination of this Agreement pursuant to Article VIII below
(the "Option Term"). The Assets shall be conveyed free and clear of all
liabilities, obligations, liens, claims and encumbrances, except only those
liabilities and obligations that are to be assumed by Mentor as expressly
provided in Section 1.4 below. From and after the Closing Date, SiTech will have
no further right to use, market or otherwise transfer the Assets. All of
SiTech's claims and rights under all existing agreements to be assigned to
Mentor shall be assigned to Mentor as of the Closing Date, and where necessary
to permit such assignment, SiTech shall use its best efforts to obtain the
written consent of the other parties to such agreements to the assignments
thereof to Mentor.

1.2 The Assets. The Assets to be sold and purchased hereunder, include, but
shall not be limited to:

(i)   all cash balances of SiTech;

(ii)  all of the accounts receivable of SiTech;

(iii) all inventories of SiTech, including without limitation all raw materials,
work in progress, finished goods (including inventories of finished products
held for packaging and/or shipping and all types of inventories which are in
transit or being held by third parties) and all production, shipping and
packaging supplies;

(iv) all prepaid expenses, including deposits and credits of SiTech;

(v) all fixed assets of SiTech, including all machinery, equipment, tools,
handling equipment and accessories and supplies;

(vi) all office furniture and furnishings, equipment and supplies of  SiTech;

(vii) all of SiTech's right, title and interest as tenant in and to leases and
interests in real property (the "Real Property"), together with all of SiTech's
right, title and interest in and to all easements, rights and appurtenances
thereto;

(viii) all of SiTech's right, title and interest in and to all plants,
buildings, structures, erections, improvements and fixtures located on or
forming part of the Real Property;

(ix)                   all of SiTech's right, title and interest in, to and
under all domestic and foreign patents, patent applications, patent licenses,
assignable software licenses, assignable know-how licenses and technology
transfer agreements, trade names, trademarks, brand names, logos, copyrights,
unpatented inventions, discoveries, conceptions, reductions to practice, service
marks, trademark and service mark registrations and applications, including
without limitation that certain License and Technology Transfer Agreement (the
"License and Technology Transfer Agreement") between SiTech and NuSil Technology
("NuSil");

(x)  all of SiTech's right, title and interest in and to trade secrets, know-how
(including, without limitation, proprietary know-how and use and application
know-how) manufacturing, engineering and other drawings, technology, technical
information, engineering data, design and engineering specifications, formulae,
processes, blueprints, sketches, schematics, flow sheets, flow diagrams,
magnetic media such as audio tapes, computer disks, micromedia such as microfilm
and microfiche, promotional literature and similar data, including without
limitation the Master Device Files (as defined in the Supply Agreement) (all
rights referred to in 1 .2(ix) and 1.2(x) together referred to as the
"Intellectual Property");

(xi)  all of the Business's existing books, general, financial, tax and
personnel records, correspondence and other documents, records and files, and
all data systems and customer information to enable Mentor to continue the
design, manufacture and sale of the Business's products and services;

(xii) the full benefit of all leases of, and conditional sales contracts and
title retention agreements relating to, machinery and equipment of which SiTech
is lessee;

(xiii)  the full benefit of all contracts or commitments to which SiTech is
entitled, including without limiting the generality of the foregoing,

(A)   all unfilled orders received by SiTech; and

(B)   all forward commitments to SiTech for fixed assets, subleases, services,
inventory, supplies or materials entered into in the usual and ordinary course
of the Business, whether or not there are any written contracts with respect
thereto;

(xiv)                 the full benefit of all licenses, and all registrations
and permits of SiTech pertaining to environment, health and safety matters, and
all other assignable registrations and permits;

(xv)                  the goodwill of SiTech;

(xvi)                 all computer aided design and other product development
equipment of SiTech; and

(xvii)                all claims, causes of action, rights of recovery, refunds
and rights of set-off of any kind of SiTech, except insofar as necessary to
offset a claim against SiTech but for which SiTech does not recover money.

(xviii)                all insurance proceeds and the full benefit of all
insurance policies of SiTech, including without limitation those described in
Section 3.12 hereof.

1.3       Excluded Assets. Notwithstanding the provisions of Section 1.2 above
to the contrary, the Assets shall not include:

(i)                     SiTech's minute book, membership or other ownership
ledger and records and tax records not necessary for Mentor to continue the
Business; and

(ii)                    assets related to employee benefit plans which are not
assumed by Mentor.

1.4       Liabilities.

(a)        Assumed Liabilities. Subject to Section 1.4(b) below, Mentor shall
assume, pay, fulfill, perform or otherwise discharge SiTech's liability for (i)
post-Closing obligations under the facility and equipment leases of SiTech as of
the Closing Date on terms acceptable to Mentor and the lessorsthereunder; (ii)
contracts and accounts payable relating to the purchase of inventory, sale of
products and similar agreements that may arise prior to the Closing Date in the
ordinary course of operations of the Business in accordance with SiTech's prior
practice; (iii) SiTech's bank line of credit or other indebtedness for borrowed
money; (iv) all sales and transfer taxes and fees, if any, generated by the
exercise by Mentor of its Option hereunder and its purchase of the Assets hereby
and (v) any accrued but unpaid obligations of SiTech to make distributions under
Section 1.6(a) hereof, all pursuant to an agreement governing the assumption of
liabilities to be executed by SiTech and Mentor in the form attached hereto as
Exhibit A (the "Assignment and Assumption Agreement").

(b)        Excluded Liabilities. Except as provided in the Assignment and
Assumption Agreement, Mentor shall not assume, pay, perform, defend or discharge
any, and SiTech shall solely retain, pay, perform, defend and discharge, all of
SiTech's liabilities and obligations of any and every kind whatsoever, whether
disclosed, undisclosed, direct, indirect, absolute, contingent, secured,
unsecured, accrued or otherwise, whether known or unknown, including but not
limited to:  (i) [Intentionally Omitted];  (ii) specifically excluding the tax
obligations described in Section 1.4(a)(iv) above, all income, withholding, or
other taxes or fees resulting from the transfer of the Assets and Business or
otherwise; (iii) any obligations or liabilities of SiTech to is employees,
including but not limited to accrued but unpaid payroll, accrued obligations or
liabilities under any employment or consulting agreements, employee's beneficial
interests or options to purchase beneficial interests in SiTech, employee
benefit plans or person, profit-sharing or retirement plans or vacation
arrangements; (iv) any obligations or liabilities under the Consolidated Omnibus
Budget Reconciliation Act of 1985, as amended ("COBRA"); (v) any liabilities or
expenses of SiTech, including brokers', attorneys' and other professionals' fees
incurred in negotiating, executing and completing SiTech's obligations under
this Agreement; (vi) any obligations or liabilities relating to any products
alleged to have been manufactured, or sold by SiTech and alleged to have been
defective, improperly designed or manufactured or improperly labeled; and (vii)
any obligations or liabilities arising under any Environmental Law (as defined
in Section 3.5 below) or any other law (collectively, the "Excluded
Liabilities").

1.5       Exercise of Option. Due Diligence and Closing Date.

(a)        The Option may be exercised by Mentor, in its sole discretion, by
delivering written notice (the "Option Notice") to SiTech prior to the
expiration of the Option Term. Such Option Notice shall specify the tentative
time and date of the Closing (which shall be not be less than ninety (90) days
and not more than 120 days from the date of delivery of the. Option Notice), and
shall specify the due diligence materials and information (the "Due Diligence
Information") to be furnished to Mentor to complete its due diligence
investigation in connection with its purchase of the Assets from SiTech at the
Closing. SiTech shall promptly prepare and provide to Mentor all Due Diligence
Information so requested and the. Disclosure Schedule (as defined in Section 3.1
below) to this Agreement (as updated to the Closing) within thirty (30) days
after SiTech's receipt of the Option Notice and due diligence request from
Mentor. Mentor shall approve or disapprove all of the Due Diligence Information
and the updated Disclosure Schedule within sixty (60) days after receipt thereof
(the "Due Diligence Period") and, provided Mentor shall have approved the same,
the Closing shall occur on the first business date following the expiration of
the Due Diligence Period (the "Closing Date").

(b)       In the event a Closing does not occur, for any reason, within 120 days
from the date of Mentor's delivery of an Option Notice to SiTech, this Agreement
shall continue in full force and effect until the earlier of: (i) the seven (7)
year anniversary of the Effective Date; (ii) a successful Closing pursuant to
Mentor's delivery of an Option Notice to SiTech; or (iii) the early termination
of this Agreement pursuant to Article VIII below.

1.6       Certain Tax Liabilities.

(a)        Notwithstanding any other provision of this Agreement, during each
year SiTech may distribute to each of its members an amount equal to their
respective federal and state net income tax liability resulting from their
interest in SiTech, calculated to the time immediately prior to Closing, taking
into account items of such year's income, loss, deduction and credit, and any
other nonseparately computed items of income or loss as described in Section
1366(a) of the Internal Revenue Code (the "Code") (collectively, the "SiTech
Items") imputed to such member for that year, pursuant to the terms in Section
1.6(b) below.

(b)       The tax liabilities described in Section 1.6(a) above shall be
calculated by the following method; Each member shall submit to an independent
Certified Public Accountant, mutually agreed upon by SiTech and Mentor (the
"CPA"), two sets of federal and state tax returns, with and without the SiTech
Items.  The CPA may not alter the members tax returns as submitted, but may, in
calculating the net tax effect of the SiTech items, make only those changes
necessary to correct numerical errors or to comply with federal and state law.
The aggregate difference in each members' net tax liability due to the inclusion
of the effect of such member's interest in SiTech, as determined by the CPA,
shall be distributed to each member by SiTech on either an annual or quarterly
basis, to coincide with each member's filing obligations, within 30 days of the
CPA completing his or her review of each member's tax returns. The expenses
associated with the CPA will be borne by SiTech in the ordinary course of
business.

(c)        After the Closing Date, and solely with respect to each annual or
quarterly tax period for a member (i) that either includes the Closing Date or
for which distributions pursuant to Section 1.6(a) could not reasonably have
been made prior to the Closing Date due to the time requirements set forth in
Section 1.6(b) above and (ii) for which distributions have not been made to such
member pursuant to Section 1.6(a), Mentor hereby agrees to distribute to each of
the members of SiTech (who are members of SiTech as of the Closing Date) an
amount equal to their respective federal and state net income tax liability
resulting from their interest in SiTech, with respect and calculated to the time
ending immediately prior to Closing, taking into account the SiTech Items
imputed to such member for that year, pursuant to the terms of Section 1.6(b)
above.

ARTICLE II
PURCHASE PRICE AND CLOSING

 2.1       Purchase Price. The aggregate purchase price for the Assets shall be
Fourteen Million Six Hundred Thousand Dollars ($14,600,000). Notwithstanding the
foregoing, such aggregate purchase price shall be subject to adjustment in the
event SiTech shall have failed to meet, to Mentor's satisfaction, as of the
Closing Date, one or more of the mutually agreed upon milestones set forth on
Exhibit B attached hereto required thereby to have been achieved by such time
(the "Milestones"). In such event the Purchase Price shall be adjusted by
subtracting the amount(s) set forth opposite such failed Milestone(s) on Exhibit
B attached hereto (as so adjusted, the "Purchase Price").

2.2       Allocation of the Purchase Price. The Purchase Price shall be
allocated among the Assets for all purposes in the manner set forth on Exhibit
C, which shall be prepared by Mentor and attached hereto on the Closing Date,
and each of the parties shall file all applicable federal, state and local
income tax returns and other forms with ail applicable tax authorities on a
basis consistent therewith.

2.3              Closing.

(a)       Upon exercise of the Option by Mentor, the Closing shall occur on the
Closing Date at the offices of Mentor, 5425 Hollister Avenue, Santa Barbara,
California 93111, or such other date and place as the parties mutually agree.

(b)        At the Closing, subject to Article VI below, SiTech shall deliver to
Mentor:

(i)         a duly executed Bill of Sale substantially in the form attached
hereto as Exhibit D;

(ii)         duly executed assignments of SiTech's right, title and interest in
and to, or licenses to practice, the Intellectual Property;

(iii)                   duly executed assignments of SiTech's right, title and
interest in, to and under each contract and license to be assigned pursuant to
this Agreement;

(iv)                   evidence of the release of all liabilities, obligations,
liens, claims and encumbrances on or against the Assets;

(v)                    such other instruments of assignment or conveyance as
Mentor may reasonably request as necessary or appropriate to vest in Mentor good
and marketable title to the Assets; and

                                    (vi)                  possession of all
tangible assets of the Business.

(c)        At the Closing, subject to Article V below, Mentor shall pay the
Purchase Price to SiTech by wire transfer of immediately available federal funds
to an account designated by SiTech, subject to escrow of the Holdback (as
defined in and pursuant to Section 2.4 below) and the Purchase Price adjustment
described in Section 2.1 above.

2.4       The Holdback.

(a)        At the Closing, Two Million Dollars ($2,000,000) of the Purchase
Price (the "Holdback") shall be deposited in an interest bearing escrow account
with a party to be mutually agreeable to Mentor and SiTech as escrow agent (the
"Escrow Agent"), to be held and administered in accordance with the terms and
conditions set forth in this Section 2.4. Mentor and SiTech shall share equally
the expenses associated with such escrow account.

(b)       If the Holdback has not been released to Mentor pursuant to Section
2.4(d) hereof and no claims by Mentor to the Escrow Agent have been made for the
release of any of the Holdback on the first business day which is one (1) year
following the Closing Date, the Escrow Agent shall release and deliver One
Million Dollars ($1,000,000) of the Holdback to SiTech, without the necessity
for any further instruction from either Mentor or SiTech.

(c)        Subject to Section 2.3(d) hereof, the Escrow Agent shall release the
Holdback (or such portion of the Holdback that SiTech is entitled to receive
after subtracting any of the Holdback released to Mentor in recovery of Damages
(as defined in Section 7.1 below) pursuant to Section 2.3(d) hereof or any of
the Holdback released pursuant to Section 2.3(b) hereof) on the first business
day which is two (2) years following the Closing Date, and on such date the
Escrow Agent shall release and deliver all or such portion of the Holdback
including interest to which SiTech is entitled to SiTech, without the necessity
for any further instruction from either Mentor or SiTech.

(d)       Mentor shall be entitled to recover any Damages that may be suffered
by Mentor and that are indemnifiable pursuant to Article VII below against the
Holdback. The applicable parties hereto shall negotiate in good faith for a
reasonable period of time (prior to seeking judicial resolution) regarding the
amount of Damages that are indemmfiable. Upon a final settlement between the
applicable parties or judgment by a court of competent jurisdiction as to the
mutually agreed or judicially determined amount of the Damages that are
indemnifiable, that portion of the Holdback equaling the amount of the Damages
to which Mentor is entitled to recover shall be released by the Escrow Agent to
Mentor to satisfy such Damages.

(e)        Mentor and SiTech hereby agree to execute and deliver any agreement
(the "Escrow Agreement") reasonably required by the Escrow Agent which sets
forth the rights and obligations of the Escrow Agent with respect to the escrow
and re sale of the Holdback.

2.5       Certain Distributions. In the event distributions are made to members
of SiTech for ongoing income tax liability, as provided for in Section 1.6 of
this Agreement, and such distributions in the aggregate exceed or will exceed
forty-three percent (43 %) of the net taxable income of SiTech as reflected on
the K-i schedules for all SiTech members during the time for which distributions
are to be made, the Purchase Price to be paid by Mentor, as set forth in Section
2.1 above, shall be reduced by an amount equal to such excess. In the event not
all distributions provided for in Section 1.6 shall have been made as of the
Closing Date, the Purchase Price shall be adjusted, if at all, as of the Closing
Date in accordance with the foregoing sentence with respect to the periods for
which distributions were actually made. As soon as practicable after all
distributions to be made pursuant to Section 1.6 have been made, Mentor shall
pay to SiTech (if the amount of clause (ii) below exceeds that of clause (i)
below), or SiTech shall pay to Mentor (if the amount of clause (i) exceeds that
of clause (ii)), an amount equal to the difference between (i) the Purchase
Price payable on the Closing Date and (ii) the Purchase Price that would have
been payable on the Closing Date if the tax and other information, with respect
to all distributions to be made pursuant to Section 1.6, required for the
calculations in the first sentence hereof were knowable and known at such time.

ARTICLE III
REPRESENTATIONS AND WARRANTIES OF SITECH AND MEMBERS

                         Except as set forth on the Disclosure Schedule attached
as Exhibit E  hereto, which specifically identifies all the relevant sections
thereon (the "Disclosure Schedule"), SiTech and, solely with respect to Sections
3.1, 3.2, 3.5(c), (d) and (e), 3.17, 3.20 and 3.21 of this Article III, the
Members, jointly and severally, represent and warrant to Mentor, as of the
Effective Date and, after the Disclosure Schedule is updated, as of the Closing
Date, as follows:

3.1       Existence. Good Standing and Authority. SiTech is a limited liability
company duly organized, validly existing and in good standing under the laws of
the State of California, and is qualified to conduct business as a foreign
limited liability company in all jurisdictions in which such qualification is
required. SiTech has all necessary power and authority and has taken all actions
necessary to enter into this Agreement, the Supply Agreement, the License and
Technology Transfer Agreement, and to consummate the transactions contemplated
hereby and thereby and to perform its obligations hereunder and thereunder, and
no other actions or proceedings on the part of SiTech are necessary to authorize
this Agreement, the Supply Agreement or the License and Technology Transfer
Agreement, or to consummate the transactions contemplated hereby and thereby.
This Agreement and each of the Supply Agreement and the License and Technology
Transfer Agreement has been duly and validly executed and delivered by SiTech,
and constitutes a legal, valid and binding obligation of SiTech, enforceable
against SiTech in accordance with its terms, except as enforcement may be
limited by equitable principles or bankruptcy, insolvency, reorganization,
moratorium or similar laws relating to creditors' rights generally. Neither the
execution or delivery of this Agreement, the Supply Agreement or the License and
Technology Transfer Agreement, nor the consummation of the transactions
contemplated hereby or thereby or performance hereunder or thereunder, will
violate the terms of the Articles of Organization or Operating Agreement of
SiTech.

3.2       Capitalization. The amount of authorized, issued and/or outstanding
ownership or membership interests of or in SiTech (the "SiTech Membership
Interests"), as applicable, are as set forth in the Disclosure Schedule. Except
as set forth in Section 3.2 of the Disclosure Schedule, all of the SiTech
Membership Interests have been issued by SiTech to, and are owned beneficially
or of record by, the Members, and are duly authorized, validly issued, fully
paid and nonassessable. Except as set forth in Section 3.2 of the Disclosure
Schedule, there are no options, warrants, conversion rights, rights of exchange
or other rights, plans, agreements or commitments of any nature whatsoever
(including without limitation conversion or preemptive rights) providing for the
purchase, issuance or sale of any ownership interests in SiTech or the SiTech
Membership Interests or any securities convertible into or exchangeable for any
SiTech Membership Interests.

3.3       Affiliate Relationships. Except for SiTech's contractual
arrangement(s) with Mentor, SiTech does not have, and on the Closing Date will
not have, any material interest, direct or indirect, in any supplier to or
customer of any party to any contract or other arrangement which is material to
SiTech.

3.4       Financial Statements. SiTech shall prepare and deliver to Mentor (i)
annually, the balance sheet and related statements of income and cash flows of
SiTech at and for each fiscal year beginning with the year in which the
Effective Date occurs and ending with the year immediately prior to the year in
which the Option Notice is delivered (the "Financial Statements"); (ii)
quarterly, the unaudited balance sheet and related statements of income and cash
flows of SiTech for each quarter of each fiscal year beginning with the year in
which the Effective Date occurs and ending with the quarterly period next
preceding the date of the Option Notice (the "Interim Financial Statements");
and (iii) at Mentor's written request, audited Financial Statements for any
fiscal year beginning with the year in which the Effective Date occurs and for
the period beginning with the beginning of the fiscal year in which the Option
Notice is given and ending on the date of the Option Notice (the "Audited
Financial Statements"). As of the Closing, the internal books and records of
SiTech from which the Financial Statements, the Interim Financial Statements and
the Audited Financial Statements are prepared will not contain any information
which is false or misleading. All Financial Statements, Interim Financial
Statements and Audited Financial Statements (i) will be prepared in accordance
with such books and records; (ii) will be prepared in accordance with SiTech's
accounting policies and principles, and will be in accordance with generally
accepted accounting principles consistently applied ("GAAP"); and (iii) will
present fairly SiTech's financial position and results of operations at the
dates and for the periods reflected therein.

3.5       Absence of Certain Changes. Notwithstanding anything to the contrary
in this Agreement, from the Effective Date until the Closing Date, SiTech shall
not, and solely with respect to Sections 3.5(c), (d) and (e) hereof, the Members
shall not and shall not permit

SiTech to, do or permit any of the items listed below. Notwithstanding the
foregoing sentence, -Mentor may waive any and all objections it may have with
respect to such action, and such

waiver and consent shall be deemed for all purposes to have been given with
respect to a proposed (and not then current) activity described in this Section
3.5 if, within 15 days of receiving notice of a proposed action, Mentor does not
deliver to SiTech in writing an objection to such action and the basis therefor.

(a)        permit to occur any Material Adverse Effect (as defined in Section
5.6 below);

(b)       increase the compensation paid or payable by SiTech, other than in the
ordinary course of business, to any of its officers, directors, employees or
agents;

(c)        (i) except as set forth in Section 1.6 hereof, pay any compensation
to any member of SiTech, (except in his, her or its capacity as a full-time,
on-site employee of SiTech; or (ii) pay compensation to any employee of NuSil
who remains employed by NuSil in any capacity;

(d)       except as set forth in Section 1.6 hereof, declare, set aside or pay
dividends or distributions in respect of ownership interests m SiTech including
SiTech Membership Interests (except in the event and to the extent SiTech's
members' equity (as determined in accordance with GAAP) at such time is equal to
or greater than Seven Million Dollars ($7,000,000)), or directly or indirectly
redeem, purchase or otherwise acquire any such ownership interests or agree to
do any of the foregoing; provided, however, that no such declaration, set aside
or payment, or agreement to do same, may occur if SiTech is liable for any bank
line of credit or other indebtedness for borrowed money, or trade or other debt,
other than accounts payable incurred in the ordinary course of business and not
more than thirty (30) days past due.

(e)        issue, transfer, sell of pledge any SiTech Membership Interests or
other securities, or any commitment, option (other than options to purchase
additional SiTech Membership Interests which may be reserved for grant to
employees and consultants of SiTech), right or privilege under which SiTech is
or may become obligated to issue any SiTech Membership Interests or other
securities;

(f)        incur any indebtedness, except such as may have been incurred or
entered into in the ordinary course of business;

(g)        make any loan or agree to make any loan, or become liable or agree to
become liable as a guarantor with respect to any loan (other than the initial
capitalization requirements of SiTech as set forth in the Disclosure Schedule);

(h)        waive or compromise any right or rights of material value or any
payment, direct or indirect, of any material debt, liability or other
obligation;

(i)         change the accounting methods, practices or policies followed by
SiTech from those in effect on the Effective Date;

(j)        sell, assign or transfer any patents, trademarks, copyrights, trade
secrets, know-how or other intangible assets or Intellectual Property of
material value;

(k)       purchase or otherwise acquire, sell, lease, dispose of, mortgage,
pledge or subject to any lien or encumbrance, any of its material property or
assets, tangible or intangible, or agree to do any of the foregoing, except in
the ordinary course of business and for any single purchase or event (or group
or series thereof, to the extent reasonable to be viewed as a single ongoing
transaction or occurrence) in an amount not greater than (i) One Hundred
Thousand Dollars ($100,000) with respect to inventory or raw materials
purchases, or (ii) Fifty Thousand Dollars ($50,000) with respect to fixed assets
or other purchases and events; provided, however, that such dollar limits shall
not apply with respect to the start-up costs of the Texas Facility and which
start-up costs, to the extent conducted reasonably, shall be considered to be in
the ordinary course of business for the purposes of this Section 3.5(k);

(1)       terminate or lose (i) any material contract, lease, license or other
agreement to which it is, as of the Effective Date, or becomes thereafter,
during the Option Term, a party; or (ii) any certificate or other authorization
it requires for the continued operation of any material portion of the Business;

(m)       agree or commit to do any of the things prohibited by this Section
3.5.

3.6       Properties. SiTech does not own or hold tide to any real properly.
With respect to all real and personal property leased by it, SiTech is in
compliance in all material respects with such leases and holds a valid leasehold
interest free of any liabilities, obligations, liens, claims or encumbrances of
any kind whatsoever.  Set forth in the Disclosure Schedule is: (i) a list of all
leases or rental contracts under which SiTech is a lessee, lessor, sublessee or
sublease and (ii) a list of all equipment used by SiTech in the operation of the
Business which is owned or leased by SiTech and which had an original cost of
$25,000 or more.  SiTech has beneficial ownership of, and good and marketable
title to, all personal property used in its operations or necessary for the
conduct of the Business, and such property is subject to no mortgages, pledges,
loans, liabilities, obligations, liens, claims or encumbrances of any kind
whatsoever. All real and tangible personal property, including machinery,
equipment and fixtures, currently used by SiTech in the operation of the
Business is in good operating condition and repair, ordinary wear and tear
excepted, and is adequate and suitable for the purposes for which it is
presently being used. To the best knowledge of SiTech, all improvements on owned
or leased property used by SiTech in the operation of the Business and the
present use thereof are in accordance with all applicable laws. The value of any
fixed asset used by SiTech in the operation of the Business has not been written
up or down, other than pursuant to depreciation or amortization expenses in
accordance with GAAP and past practice.

3.7       Inventory. SiTech's inventory consists, and at the time of Closing
will consist, solely of inventory of the kind and quality regularly and
currently used in the Business.

3.8       Indebtedness. The Disclosure Schedule contains a complete list of each
-and every agreement or other instrument under which SiTech has outstanding
indebtedness for borrowed money equal to or greater than $25,000. Prior to the
Effective Date SiTech shall furnish Mentor with true and correct copies of each
such agreement and instrument, including all amendments with respect thereto
(and, with respect to such agreements and instruments entered into after the
Effective Date, SiTech shall furnish Mentor with true and correct copies of each
such agreement and instrument, including all amendments with respect thereto,
prior to the Closing). SiTech is not in default in any material respect under
any such agreement or instrument and, to the best knowledge of SiTech, no party
to any such agreement or instrument is in default in any material respect
thereunder.

3.9       Litigation. Except as set forth on the Disclosure Schedule, there are
no actions, causes of action, claims, suits, proceedings, orders, writs,
investigations, injunctions or decrees pending or, to the best knowledge of
SiTech threatened, against SiTech or affecting the operations of SiTech (or its
properties, assets or the businesses) or the consummation of the transactions
contemplated herein, at law or in equity, or before or by any court or any
governmental department, commission, board, bureau, agency or instrumentality,
domestic or foreign. SiTech is in compliance with all applicable laws and
regulations.

3.10     Taxes. SiTech has (i) duly and timely filed or caused to be filed all
federal, state and local tax returns required to be filed, if any, prior to the
Closing Date which relate to SiTech or with respect to which SiTech is liable or
otherwise is in any way subject, and

(ii)  has paid all such federal, state and local taxes due and payable. No tax
liabilities, disallowances or assessments relating to the Business, the Assets
or the employees or independent contractors of SiTech are outstanding, and to
the best knowledge of SiTech there is no basis for any such liabilities,
disallowances or assessments.

3.11  Employees and Service Providers.  SiTech had not been and is not currently
involved in any labor discussion with any group seeking to become the bargaining
unit for any of SiTech's employees.  The Disclosure Schedule contains a listing
of (i) each employment, consulting, severance, deferred compensation, bonus,
ownership interest option, purchase or appreciation and any other employee
benefit plan (whether or not in writing) providing for compensation or other
benefits to employees (including officers), or independent contractors,
individually or as a group, to which SiTech is a party or by which it is bound;
(ii) each "employee pension benefit plan" as defined in Section 3(2) of the
Employee Retirement Income Security Act of 1974 ("ERISA") and not exempted under
Section 4(b) or Section 201 of ERISA maintained by SiTech or to which SiTech is
required to contribute including any multi-employer pension plan; and (iii) each
"employee welfare benefit plan" as defined in Section 3(1,) of ERISA maintained
by SiTech or to which SiTech contributes or is required to contribute. SiTech
has complied in all material respects with all applicable laws, rules and
regulations relating to employment. All of SiTech's employee benefits plans, as
defined in Section 3(3) of ERISA, including all benefit plans subject to Title
IV of ERISA, in effect at any time since inception of SiTech are now, and have
always been, established, maintained and operated in accordance, in all material
respects, with all applicable laws (including, without limitation, ERISA and the
Internal Revenue Code) and all regulations and interpretations thereunder and in
accordance with their plan documents.

3.12     Insurance. The following insurance policies are in full force and
effect and have been in full force and effect, without gaps, continuously since
the Effective Date:

(i)         worker's compensation insurance coverage in the amount required by
Texas law;

(ii)        general comprehensive liability insurance, with contractual
liability and property damage endorsements in the minimum amount of Two Million
Five Hundred Thousand Dollars ($2,500,000)each occurrence and in the aggregate,
including coverage for business interruption (with coverage limits and terms
customary and reasonable for the industry); and

(iii)       environmental impairment liability insurance for non-sudden and
accidental occurrences, if required by applicable law or regulation.

Copies of the above policies have been made or will be made available to Mentor
for inspection. SiTech is not aware of any facts concerning SiTech, the Business
or its operations, assets and liabilities, contingent or otherwise, upon which
an insurer might be justified in reducing coverage or increasing premiums on
existing policies and all such insurance polices can be maintained in full force
and effect without substantial increase in premium or reducing the coverage
thereof following the Closing Date. All insurance coverage shall consist of 100%
replacement coverage, to the extent applicable.

3.13          Contracts and Permits.

(a)        The Disclosure Schedule contains a true and complete list of each of
the following written or oral contracts, agreements or other arrangements to
which SiTech is a party as of the Effective Date (to be updated prior to Closing
to describe all contracts, agreements or other arrangements to which SiTech has
become a party after Effective Date) and which are not already disclosed
pursuant to other provisions in the Agreement:

(i)         all loan agreements, indentures, debentures, notes or letters of
credit relating to the borrowing of money or to mortgaging, pledging or
otherwise placing a lien on any material asset of SiTech;

(ii)        all leases or agreements under which SiTech is lessee of, or holds
or operates, any property, real or personal, owned by any other party, except
for any lease under which the aggregate annual rental payments do not exceed
$5,000;

(iii) all contracts and agreements that (A) involve the payment or potential
payment, pursuant to the terms of any such contract or agreement, by SiTech of
more than $25,000 annually, and (B) cannot be terminated within thirty (30) days
after giving notice of termination without resulting in any cost or penalty to
SiTech;

(iv) a list of the Master Device Files with respect to each product manufactured
by SiTech; and

(v)        all material permits, licenses and other, certificates or
authorizations issued to SiTech by any governmental authority having
jurisdiction over the Texas Facility (collectively, the "Permits").

(b)       Each contract disclosed in the Disclosure Schedule is in full force
and effect and constitutes a legal, valid and binding agreement, enforceable in
accordance with its terms, of each party thereto and will continue to be legal,
valid, binding and enforceable after the Closing. SiTech has performed all of
its required obligations under, and is not, in any material respect, in
violation or breach of or default under, any contract except as set forth in the
Disclosure Schedule. Except as set forth on the Disclosure Schedule, the Permits
are, and as of the Closing will be, in full force and effect and the continuing
validity and effectiveness of such Permits will not be affected in any manner by
the sale and transfer of the Assets to Mentor as herein contemplated.

3.14     Compliance with Law: Governmental Consents. The Business has been and
is being conducted by SiTech in compliance with all laws, rules, regulations and
licensing requirements applicable thereto, except where failure to be so in
compliance would not have a Material Adverse Effect (as defined in Section 5.6
below). SiTech is not aware of any facts which might form the basis for a claim
that any material violation of such laws exists. There are no unresolved notices
of deficiency or charges of violation brought or, to the best knowledge of
SiTech, threatened against SiTech, under any federal, state or local laws or
regulations. Except for any filing requirements under the HSR Act (as defined in
Section 4.3 below) and except as set forth on the Disclosure Schedule attached
hereto, no consent, approval, order or authorization of, or registration.
qualification, designation,. declaration or filing with, any federal, state or
local governmental authority on the part of SiTech is required in connection
with the execution, delivery and performance by SiTech of this Agreement, the
consummation of the transactions contemplated hereby, or Mentor's operation of
the Business following the Closing Date.

3.15     Environmental Matters.

(a)        For purposes of this Agreement, the term "Environmental Laws" shall
mean all federal, state, local and foreign laws, codes, regulations, common law,
requirements, directives, orders and administrative or judicial interpretations
thereof, all as in effect on the date hereof or on the Closing Date, that may be
enforced by any governmental or regulatory authority, relating to pollution, the
protection of the environment or the emission, discharge, disposal, release or
threatened release of Hazardous Materials in or into the environment, and the
term "Hazardous Materials" shall mean pollutants, contaminants or chemical,
industrial, hazardous or toxic materials or wastes.

(b)       (i) SiTech has not received any notices, directives, violation
reports, actions or claims from or by (A) any federal, state or local
governmental agency concerning SiTech and any Environmental Law, or (B) any
person alleging that, in connection with Hazardous Materials, conditions at any
real property owned or leased by SiTech have resulted in or caused or threatened
to result in or cause injury or death to any person or damages to any property,
including, without limitation, damage to natural resources; and to the best
knowledge of SiTech no such notices, directives, violation reports, actions,
claims, assessments or allegations exist; (ii) throughout the period of
operation of any real property by SiTech, SiTech has operated and continues to
operate such real property in compliance with all Environmental Laws and in a
manner which should not give rise to any liability under any Environmental Laws
and (iii) SiTech is not aware of any facts, events or conditions (including,
without limitation, the generation, treatment, transport, storage, emission,
disposal, release or other placement, deposit or location of any substance)
which materially interfere with or prevent continued compliance by SiTech with,
or give rise to any present or potential liability (including with respect to
past activities) under any Environmental Laws.

3.16     Operation of Facilities. SiTech shall at all times operate the Texas
Facility and manufacture its products in conformance with ISO-9002 and current
Good Manufacturing Practices Quality Systems Regulations (the "GMPs"), as
promulgated by the United States Food and Drug Administration.

3.17     Consents of Non-Governmental Third Parties. No consent, waiver or
approval of any non-governmental third party is necessary for the consummation
by SiTech and the Members of the transactions contemplated by this Agreement,
the Supply Agreement or the License and Technology Transfer Agreement.

3.18     Intellectual Property Rights. SiTech owns all right, title and interest
in and to or has the unrestricted right to grant licenses to, fully exploit and
exercise all of the Intellectual Property necessary in any material respect for
the ownership, maintenance and operation of the Business, all as more
specifically described in the Disclosure Schedule.  The Intellectual Property
does not infringed or otherwise violate the rights of any third party.  There
are no claims or allegations asserted by any person challenging such ownership
or licenses, or the validity or enforceability of the Intellectual Property and
all such Intellectual Property is freely transferable.  To the best knowledge of
SiTech, the Intellectual Property is not being infringed or otherwise violated
by any party.  The consummation of the transactions contemplated by this
Agreement (and specifically the purchase by Mentor of the Assets of SiTech) and
the Supply Agreement, will not, in any way, alter or impair SiTech's ownership
of, and/or rights, in the Intellectual Property, nor its ability to freely
transfer such rights to Mentor. As of the Closing, Mentor will have full
ownership of, and/or rights with respect to, the Intellectual Property free and
clear of all liabilities, obligations, liens, claims and encumbrances, which
Intellectual Property will constitute after the transfer to Mentor all of the
Intellectual Property necessary in any material respect for the ownership,
maintenance and operation of the Business as conducted at the time of Closing.

3.19         No Undisclosed Liabilities. SiTech has no liabilities other than as
disclosed herein (absolute, accrued, fixed, contingent, liquidated, unliquidated
or otherwise) which may have a Material Adverse Effect (as defined in Section
5.6 below).

3.20         No Fraudulent Conveyance. SiTech and the Members have not disposed
of or transferred any of SiTech's assets in a manner that would constitute, and
the consummation by SiTech and the Members of the transactions contemplated
hereby will not constitute, a fraudulent conveyance or fraud on creditors of
SiTech under applicable law.

3.21        Representations Complete. Neither the representations and warranties
made by SiTech and, as applicable, the Members herein nor any statement made in
any Exhibit, Schedule or certificate furnished pursuant to this Agreement,
contains as of the Effective Date or as of the Closing Date, as applicable, any
untrue statement of a material fact, or omits to state any material fact
required to be stated therein, or necessary in order to make the statements
made, in light of the circumstances under which they were made, not misleading.

ARTICLE IV
COVENANTS OF SITECH AND THE MEMBERS

4.1           Development of Business. From the Effective Date until the Closing
Date, SiTech shall use its best efforts to carry on the development of the
Business in order for SiTech to achieve the Milestones set forth on Exhibit B
hereto, and to fulfill its obligations under this Agreement, the Supply
Agreement and the License and Technology Transfer Agreement.

4.2          Conduct of Business.

(a)        Notwithstanding anything to the contrary in this Agreement, from the
Effective Date until the Closing, SiTech shall not, and specifically with
respect to Sections 4.2(a)(xii) and (xiii), the Members shall not permit SiTech
to, do or permit any of the items listed below in thisSection 4.2(a). 
Notwithstanding the foregoing sentence, Mentor may waive any and all objections
it may have with respect to such action under this Section 4.2(a), and such
waiver and consent shall be deemed for all purposes of such Section to have been
given with respect to a proposed (and not then current) action described in this
Section if, within 15 days of receiving notice of a proposed action , Mentor
does not deliver to SiTech in writing an objection to such action and the basis
therefore.

(i)         incur any additional indebtedness, or guarantee any indebtedness or
obligation of any other party; provided, however, that SiTech may obtain a
working capital line of credit of not more than $100,000;

(ii)        issue, redeem or purchase any of SiTech's Membership interests or
other ownership interests in SiTech or securities convertible into same or grant
or issue any options (other than options to purchase additional SiTech
Membership Interests which may be reserved for grant to employees and
consultants of SiTech), warrants or rights to subscribe for SiTech Membership
Interests in SiTech or securities convertible into same or commit to do any of
the foregoing;

(iii) enter into any agreement to manufacture or sell any products or materials
of any nature to any party other than the products and materials to be purchased
by Mentor under the Supply Agreement;

(iv) enter into, amend or terminate any material agreement or arrangement, other
than in the ordinary course of business;

(v) increase the compensation payable or to become payable to any of SiTech's
officers, employees or agents (except in the ordinary course of business), or
adopt or amend any employee benefit plan or arrangement other than to adopt a
option or bonus plan under which options to purchase beneficial interests in
SiTech may be reserved for grant to employees and consultants of SiTech);

(vi) enter into any employment contract or agreement with any existing or
prospective employee (other than to the extent such individual agrees to be
bound by confidentiality provisions or by which he or she may receive or
purchase beneficial interests in SiTech), including without limitation, the
payment of or entering into obligations with respect to any severance benefits
("Severance Benefits");

(vii) pay any obligation or liability, fixed or contingent, other than in the
ordinary course of business;

(viii) cancel, without full payment, any note, loan or other obligation owing to
SiTech;

(ix) acquire or dispose of any properties or assets used in the Business except
in the ordinary course of business;

(x)        create or suffer to be imposed any mortgage, security interest,
charge, liability, obligation, lien, claim or encumbrance on or against any of
SiTech's properties or assets;

(xi)       engage in any business, activity or transaction outside the ordinary
course of the Business as proposed to be conducted as of the Effective Date;

(xii) make or adopt any change in the Articles of Organization or Operating
Agreement of SiTech as in force and effect on the Effective Date (except to the
extent of increasing the authorized SiTech Membership Interests for issuance to
present NuSil or SiTech employees as of the date hereof, or in connection with
issuances of beneficial interests in SiTech to employees); or

(xiii) take any action, or omit to take any action, within its control, that
would cause, and shall promptly notify Mentor in writing of any event or
occurrence which causes, any of the representations and warranties set forth in
Article III hereof, to the extent applicable to SiTech or such Members, to
become untrue, incomplete or inaccurate in any material respect prior to or as
of the Closing Date.

(b)       From the Effective Date until the Closing Date, except as otherwise
expressly permitted in this Agreement, SiTech shall:

(i)         operate the Texas Facility and manufacture its products in
conformance with ISO-9002 and with the GMPs, with all relevant United States
federal and state laws and regulations applicable to the products manufactured
by SiTech and with such other foreign regulatory authorities as requested by
Mentor;

(ii)          maintainSiTech's insurance policies at the coverage levels
described in Section 3.12 hereof, and not take any action to terminate or modify
such insurance policies;

(iii)        maintainSiTech's books and records consistent with SiTech's past
practices and policies and in accordance with GAAP;

(iv)        maintain in good working condition, ordinary wear and tear excepted,
and in compliance in all material respects with all applicable laws and
regulations, all fixed assets owned, leased or operated, as the case may be, by
SiTech;

(v)        (A) observe and perform, and remain in compliance with, SiTech's
obligations in agreements and contracts the breach or violation of which would
have, individually or in the aggregate, a Material Adverse Effect (as defined in
Section 5.6 below) and (B) not enter into any agreements or contracts outside
the ordinary course of business or which would require payments by SiTech, for
any single agreement or contract (or group or series thereof, to the extent
reasonable to be viewed as a single ongoing transaction), over any period of
twelve (12) months of more than (i) One Hundred Thousand Dollars ($100,000) with
respect to inventory or raw materials purchases, or otherwise (ii) Fifty
Thousand Dollars ($50,000); provided, however, that such dollar limits shall not
apply with respect to the start-up costs of the Texas Facility and which
start-up costs, to the extent conducted reasonably, shall be considered to be in
the ordinary course of business for the purposes of this Section 4.2(b)(v); and
provided, further, that notwithstanding the foregoing Section 4.2(b)(v)(B),
Mentor may waive any and all objections it may have with respect to such
contract or agreement under Section 4.2(b)(v)(B), and such waiver and consent
shall be deemed for all purposes of such Section to have been given with respect
to a proposed (and not then current) contract or agreement if, within 15 days of
receiving notice of a proposed contract or agreement, Mentor does not deliver to
SiTech in writing an objection to such contract or agreement and the basis
therefor.

(vi) use its best efforts to maintain all Permits held by SiTech or under which
it operates or conducts the Business in full force and effect.

4.3       Necessary Consents. Certificates and Films.

(a)        Prior to the Closing, SiTech, and specifically with respect to
Sections 4.3(a)(i) and (iv), the Members, shall use their reasonable best
efforts to (i) take, or cause to be taken, all appropriation action, and do, or
cause to be done, all things necessary, proper or advisable under applicable law
or otherwise to consummate and make effective the transactions contemplated as
promptly as practicable, including without limitation voting in favor of same,
(ii) obtain from any governmental authorities any consents, licenses, permits,
waivers, approvals, authorizations or orders required to be obtained by SiTech
or any of SiTech's subsidiaries in connection with the authorization, execution
and delivery of this Agreement and the consummation of the transactions
contemplated, (iii) use its best efforts to obtain such estoppel certificates
from the landlord of the Texas Facility as required by Mentor (the "Estoppel
Certificates"), (iv) make all necessary filings, and thereafter make any other
required submissions, with respect to this Agreement and the transactions
contemplated herein required under the Hart-Scott-Rodino Antitrust Improvements
Act of 1976 (the "HSR Act") and the rules and regulations promulgated
thereunder, and any related governmental request thereunder, if applicable, and
any other applicable law; provided that SiTech and Mentor shall cooperate with
each other in connection with the making of all such filings, including
providing copies of all necessary documents to the other and its advisors prior
to filing, and, if requested, accepting all reasonable additions, deletions or
changes suggested in connection therewith.

(b)       Without limiting the generality of its undertakings pursuant to
Section 4.3(a) above, SiTech shall (i) use its reasonable best efforts to
prevent the entry in a judicial or administrative proceeding brought under any
antitrust law by any governmental authority with jurisdiction over enforcement
of any applicable antitrust laws or any other party of a preliminary injunction
or other order that would make consummation of the transactions contemplated
hereby in accordance with the terms of this Agreement unlawful or would prevent
or delay such consummation; and (ii) take promptly, in the event that such an
injunction or order has been issued in such a proceeding, all steps necessary to
prosecute an appeal of such injunction or order; provided, however, that SiTech
shall not be required to undertake more than one such appeal.

            4.4                   Access to Information.  SiTech shall give
Mentor and its accountants, legal counsel and other representatives full access,
during normal business hours throughout the period commencing on the date hereof
and through the Closing Date, to all of the properties, books, contracts,
commitments and nonprivileged records relating to the Business, the Assets and
the liabilities of SiTech, and will furnish Mentor, its accountants, legal
counsel and other representatives during such period all such information
concerning its affairs as Mentor may reasonably request, including but not
limited to the annual delivery of the Financial Statements or the Audited
Financial Statements, as applicable, and the quarterly delivery of the Interim
Financial Statements pursuant to Section 3.4 above. Mentor shall also have the
right to audit SiTech to ensure conformance by SiTech with ISO-9002 and
conformance with applicable regulatory requirements, including the GMPs,
provided that such audits will be scheduled during normal business hours upon at
least thirty (30) days prior written notice to SiTech. Any furnishing of
information pursuant hereto by Mentor shall not affect Mentor's right to rely on
the representations, warranties and covenants made by SiTech and, to the extent
applicable, the Members in this Agreement.

4.5       Certain Defaults: Litigation: Changed Circumstances. SiTech will give
prompt notice to Mentor of:

(a)        any notice of default received by SiTech subsequent to the date of
this Agreement and through the Closing Date under any instrument or agreement to
which SiTech is a party or by which SciTech or the Assets are bound, which
default could, if not -remedied, have a Material Adverse Effect (as defined in
Section 5.6 below) or which would render incorrect any representation or
warranty made herein; - -

(b)       any suit, action, proceeding or investigation instituted or threatened
against or affecting SiTech subsequent to the date of this Agreement and prior
to the Closing which, if adversely determined, could have a Material Adverse
Effect (as defined in Section 5.6 below) or which would render incorrect any
representation or warranty made herein; and

(c)        any change in circumstances or action resulting in a breach of any
representation and warranty set forth in Section 3 above, including without any
limitation any actions in breach of Section 3.5 above.

4.6       Other Negotiations. Prior to the Closing, or such earlier date on
which this Agreement is terminated in accordance with its terms, SiTech and the
Members will not, and SiTech and the Members will cause SiTech's officers,
directors, employees, agents and representatives not to, directly or indirectly,
initiate discussions or negotiate, or authorize any person or entity to discuss
or negotiate with any other, or entertain or consider any inquiries or proposals
received from any other person or entity, concerning the possible disposition of
the Business or the Assets, in whole or in part. l)during such time, SiTech and
the Members will not furnish any information concerning SiTech to any person or
entity other than Mentor for the purpose of, or with the intent of, permitting
such person or entity to evaluate a possible acquisition of the Business or the
Assets, in whole or in part. SiTech and the Members will give prompt notice to
Mentor of any inquiries or proposals received by SiTech or the Members from any
third party concerning the disposition of the Business and the Assets.

4.7              Confidential Information.

(a)        From time to time during the term hereof, one or more of the parties
may acquire form one or more of the other parties hereto certain secret,
confidential or proprietary information (whether or not reduced to writing and
whether or not patentable or copyrightable) which is or in any manner may be
related to the Materials (as defined in the Supply Agreement) or the business of
another party hereto (collectively, "Proprietary Information"). Any party
receiving Proprietary Information of another party hereunder shall keep strictly
secret and confidential and shall not, either during or after the term of this
Agreement, without such other party's prior written consent, disclose to any
third party or use such Proprietary Information; provided, however, that such
party may disclose such Proprietary Information to those of its employees who
reasonably need to know such Proprietary Information in order to perform their
duties under this Agreement or under the Supply Agreement. Each party shall use
his or its best efforts to compel any person or entity to whom or which such
party discloses Proprietary Information hereunder to keep such Proprietary
Information strictly secret and confidential in accordance with the provisions
of this Section 4.7.

(b)       The obligations of the parties under Section 4.7(a) above shall not
apply to:

(i) Proprietary Information that is generally known to the public at the time of
disclosure or subsequently becomes generally known to the public through no
breach of Section 4.7(a) above by any party to this Agreement;

(ii) Proprietary Information that was in the receiving party's possession prior
to disclosure hereunder;

(iii) Proprietary Information that was obtained by the receiving party in good
faith from a third party lawfully possessing and having a right to disclose the
same;

(iv) Proprietary Information that the receiving party is required by law or
court order to disclose, provided that any party receiving any subpoena or
governmental, judicial or administrative request for any Proprietary Information
of Mentor shall notify Mentor of the request immediately, and shall not disclose
such Proprietary Information absent Mentor's consent or a court order requiring
such disclosure; or

(v)         Proprietary Information that the receiving party has affirmatively
demonstrated to the disclosing party's reasonable satisfaction prior to
disclosure or use was independently developed by the receiving party without the
aid, application, reference or use in any way to Proprietary Information
received from the disclosing party.

(c)       Within thirty (30) days following the termination or expiration of
this Agreement or the request of a disclosing party hereto, the parties shall
each return all Proprietary Information belonging to the other parties and all
copies thereof, and any other records containing such Proprietary Information,
to the other parties, except that SiTech may retain copies of such Proprietary
Information to the extent necessary to meet any continuing obligations it may
have to Mentor under this Agreement.

(d)        The parties hereto acknowledge that any breach or violation of
provisions of Section 4.7(a) above will result in irreparable and continuing
damage to the other parties for which there may be no adequate remedy at law,
and the parties agree that in the event of any such breach or violation by any
of them, the injured party shall be entitled to seek both damages and injunctive
relief.

(e)        The obligations of the parties under this Section 4.7 shall survive
the Closing or termination of this Agreement and shall continue in full force
and effect in perpetuity.

(f)         SiTech shall require, prior to any person becoming a member of
SiTech, that such person agree in writing to become subject to all the
obligations of this Section 4.7 as if he, she or it were a party hereto.

4.8       [Intentionally Omitted]

4.9       Insurance. SiTech shall provide Mentor with a Certificate of
Insurance, within sixty (60) days of the Effective Date and annually thereafter
during the Option Term, verifying the insurance policies described in Section
3.12 above. SiTech covenants that anyinsurance proceeds attributable to a loss,
which may be repaired, replaced or cured, will be used solely for the purposes
of repairing, replacing or curing such loss.

4.10     Bankruptcy of Licensors. In the event any grantor or licensor of
Intellectual Property (a "Licensor") to SiTech becomes the subject of a
voluntary or involuntary bankruptcy proceeding, SiTech will not consent to
termination of any license, technology transfer or other agreement of similar
nature SiTech may have with such Licensor.

ARTICLE V
CONDITIONS PRECEDENT TO OBLIGATIONS OF MENTOR

 The obligation of Mentor to consummate the transactions contemplated by this
Agreement is subject to the satisfaction, at or before the Closing, of all the
following conditions, unless waived in writing by Mentor:

5.1       Representations and Warranties True. All representations and
warranties of SiTech and the Members in this Agreement and the Schedules and
Exhibits hereto, or in any written statement or certificate that shall be
delivered to Mentor by SiTech and the Members, respectively, under this
Agreement, shall be true and correct on and as of the Closing Date as if made on
the date thereof.

5.2       Covenants Performed.  SiTech and the Members shall have performed,
satisfied and compiled with all covenants, agreements and conditions required by
this Agreement to be performed, satisfied or complied with by SiTech and the
Members on or before the Closing Date.

5.3       Certificate.  Mentor shall have received from SiTech a certificate,
dated the Closing Date, certifying, in such detail as Mentor and its counsel may
reasonably request, that the conditions specified in this Article V have been
satisfied.

5.4       Opinion of Counsel for SiTech. Mentor shall have received an opinion
from counsel for SiTech dated the Closing Date in a form reasonably acceptable
to Mentor.

5.5       No Violations; No Actions. Consummation of the transactions
contemplated by this Agreement shall not violate any order, decree or judgment
of any court or governmental body having competent jurisdiction and no action or
proceeding shall have been instituted or threatened by any person, entity or
governmental agency which, in any such case, in the sole judgment of Mentor, has
a reasonable probability of resulting in (i) the obtaining of material damages
from Mentor; (ii) an order, judgment or decree restraining, prohibiting or
rendering unlawful the consummation of the transactions contemplated by this
Agreement; or (iii) other relief in connection therewith.

5.6       No Material Adverse Effect. During the period from the date of this
Agreement to the Closing, there shall not have occurred an event or condition
which has resultedor which reasonably may be expected to result in a material
adverse change in the business condition (financial or otherwise), operations,
properties, assets, liabilities or prospects of the Business (a "Material
Adverse Effect"), and Mentor shall have received a certificate from SiTech dated
the Closing Date to the foregoing effect. For purposes of this Agreement,
"Material Adverse Effect," as defined above, to the extent it is quantifiable,
shall mean an event which would require SiTech to make payments or otherwise
incur liability of more than $50,000 for any one item or $100,000 in the
aggregate over any period of twelve (12) months; provided, however, that
notwithstanding the foregoing sentence, a Material Adverse Effect shall not
include the specific act by SiTech of entering into any contract or other
agreement that is expressly allowed under Section 4.2(b)(v) (including by waiver
or deemed waiver by Mentor) or any occurrence that would be a violation of
Section 3.5(k) hereof but for the fact that Mentor waived (or is deemed to have
waived) its objections to such occurrence under such Section.

5.7       Authorizations. The managers, if any, and, to the extent required by
law, the members of SiTech shall have approved this Agreement and the
transactions contemplated hereby.

5.8       Documents. Unless otherwise specified hereunder, all documents and
instruments incident to the transactions contemplated by this Agreement shall be
in form and substance reasonably satisfactory to Mentor and its counsel, and
Mentor shall have received all such counterpart originals or certified or other
copies of such documents as it reasonably may request.

5.9       Delivery of Documents. Mentor shall have received all of the following
documents and other items to be delivered by SiTech and, to the extent
applicable, the Members before or at the Closing:

(a)        Documents.  The Bill of Sale, deeds, instruments of assignment, other
instruments of conveyance and transfer, the Escrow Agreement and all other
documents to be delivered by SiTech and the Members to Mentor at the Closing, in
form and substance reasonably satisfactory to Mentor. 

(b)        [Intentionally Omitted].

(c)       Resolutions. Resolutions and/or consent of the managers, if any, and,
to the extent required by law, the members of SiTech authorizing the execution,
delivery and performance of this Agreement and the transactions contemplated
hereby, certified by SiTech's Secretary as being true and correct and in full
force and effect as of the Closing Date.

(d)       Certificates of Good Standing. Certificates of Good Standing
(including tax) with respect to SiTech, issued by the Secretaries of State of
the States of California and Texas, dated within ten (10) days of the Closing
Date.

(e)        Consents. Evidence that all consents, approvals or authorizations of
or notifications to any third parties (including governmental agencies), if any,
required to sell the Assets and to consummate the transactions contemplated
hereby have been obtained by SiTech and the Members.

(f)        Opinion of Counsel. The opinion of counsel for SiTech provided in
Section 5.4above.

(g)       Certificates. Certificate from SiTech, dated the Closing Date,
containing the information required pursuant to Sections 5.3 and 5.6 above.

(h)        Estoppel Certificates. The Estoppel Certificates, if obtainable
through SiTech's best efforts.

(i)         Other Documents. Such other documents and instruments as Mentor or
its counsel reasonably shall deem necessary to consummate the transactions
contemplated hereby.

5.10     Existing Liens. All outstanding liabilities, obligations, liens, claims
and encumbrances against SiTech or any of the Assets as of the Closing Date
shall be released at or prior to the Closing.

5.11     Due Diligence. Mentor and its counsel shall have completed their due
diligence investigation of SiTech and the Business on or before the Closing
Date, and the results of such due diligence investigation shall be satisfactory
in all respects to Mentor (including approval of all Due Diligence Information
provided by SiTech and the Members to Mentor).

5.12     Schedule and Exhibits. SiTech and the Members shall have completed and
attached hereto all updated Schedules and Exhibits required by this Agreement
within five (5) business days prior to the Closing Date, and all such Schedules
and Exhibits shall be acceptable to Mentor, in its sole discretion.

5.13     Required Consents.  All consents, approvals and waivers from third
parties and governmental authorities necessary for consummation of the
transactions contemplated hereby and to the continued validity and effectiveness
of the Permits shall have been obtained without the imposition on Mentor of any
conditions, restrictions or obligations that are not acceptable to Mentor in its
sole discretion.

5.14     HSR Act. All applicable requirements under the HSR Act and the rules
and regulations promulgated thereunder, if any, shall have been met, including,
without limitation, the expiration of all applicable waiting periods thereunder,
and neither the Department of Justice nor the Federal Trade Commission shall
have raised objections to the transactions contemplated hereby.

5.15      Bulk Sales. SiTech shall have complied with all applicable bulk sales
laws, and shall have paid or made arrangements for the payment in full of all
creditors of SiTech on or prior to the Closing Date on terms satisfactory to
Mentor in its sole discretion.

5.16     Appraisals and Solvency Options. If requested by Mentor within thirty
(30) days prior to the Closing Date, SiTech shall have provided Mentor with
appraisals from one or more independent appraisers mutually acceptable to SiTech
and Mentor confirming (i) that the royalties paid by SiTech to NuSil under the
License and Technology Transfer Agreement constitute fair value paid by SiTech
for the rights and benefits received thereunder, (ii) that the exercise price to
be paid by Mentor on exercise of the Option constitutes fair value for the
Assets, and (iii) that SiTech will not be rendered insolvent by virtue of
Mentor's purchase of the Assets hereunder.

5.17     Business Judgment of Mentor. Mentor shall have deemed on the Closing
Date, in its sole and absolute discretion, that completion of the transactions
contemplated by this Agreement are in the best interest of Mentor and its
shareholders.

ARTICLE VI
CONDITIONS PRECEDENT TO OBLIGATIONS OF SITECH

The obligation of SiTech to consummate the transactions contemplated by this
Agreement is subject to the satisfaction, at or before the Closing, of all the
following conditions, unless waived in writing by SiTech:

6.1       Opinion of Counsel. Mentor shall have furnished to SiTech an opinion,
dated the Closing Date, of Brobeck, Phleger & Harrison LLP, counsel for Mentor,
in a form reasonably acceptable to SiTech.

6.2       No Violations; No Actions. Consummation of the transactions
contemplated by this Agreement shall not violate any order, decree or judgment
of any court or governmental body having competent jurisdiction and no action or
proceeding shall have been instituted or threatened by any person, entity or
governmental agency which, in any such case, in the judgment of SiTech, has a
reasonable probability if resulting in (i) the obtaining of material damages
from SiTech, (ii) an order, judgment or decree restraining, prohibiting or
rendering unlawful the consummation of the transactions contemplated by this
Agreement, or (iii) other relief in connection therewith.

6.3       Proceedings and Documents. Unless otherwise specified hereunder, all
documents and instruments incident to the transactions contemplated by this
Agreement shall be in form and substance reasonably satisfactory to SiTech and
its counsel, and SiTech shall have received all such counterpart originals or
certified or other copies of such documents as they reasonably may request.

6.4       Delivery of Documents. SiTech shall have received all of the following
documents and other items to be delivered by Mentor simultaneously with the
deliveries of SiTech pursuant to Section 5.9 above:

(a)        Documents. The Assignment and Assumption Agreement and all other
documents to be delivered by Mentor to SiTech at the Closing, in form and
substance reasonably satisfactory to SiTech.

(b)       Resolutions. Resolutions of the Board of Directors of Mentor
authorizing the execution, delivery and performance of this Agreement and the
transactions contemplated hereby, certified by Mentor's Secretary as being true
and correct and in full force and effect as of the Closing Date.

(c)        Payment of the Purchase Price. The Purchase Price, subject to the
Holdback, and any adjustments thereto provided for herein.

(d)       Opinion of Counsel. The BP&H Opinion.

(e)        Other Documents. Such other documents and instruments as SiTech or
its counsel reasonably shall deem necessary to consummate the transactions
contemplated hereby.

6.5       HSR Act. All applicable requirements under the HSR Act and the rules
and regulations promulgated thereunder, if any, shall have been met, including,
without limitation, the expiration of all applicable waiting periods thereunder,
and neither the Department of Justice nor the Federal Trade Commission shall
have raised objections to the transactions contemplated hereby.

ARTICLE VII
OBLIGATIONS OF THE PARTIES AFTER CLOSING

7.1       Indemnification by SiTech and the Members. SiTech and, solely with
respect to and to the extent of the obligations of the Members as expressly set
forth in the Agreement, the Member, jointly and severally, shall indemnify and
hold harmless Mentor and its officers, directors, employees, attorneys,
representatives, successors and assigns in respect of any and all claims,
actions, suits or other proceedings and any and all losses, costs, expenses,
liabilities, fines, penalties, interest and damages, whether to not arising out
of any claim, action suit or other proceeding, and including reasonable
attorneys' and accountants' fees and expenses and all other reasonable costs and
expenses of investigation, defense or settlement of claims and amounts paid in
settlement, (collectively, "Damages"), incurred by, imposed on or borne by
Mentor arising out of, resulting from or in any manner relating to:

(a)        the breach of any of the representations or warranties made by SiTech
and the Members in this Agreement;

(b)       the breach or the failure of performance by SiTech or the Members of
any of the covenants that they are to perform hereunder;

(c)        the payment of any taxes (including interest and penalties) of any
kind or nature imposed, whether before or after the Closing, by any government
or subdivision thereof upon the business, assets or employees of SiTech or
otherwise resulting from or relating to the respective businesses or operations
of SiTech prior to the Closing or any of its properties or assets as they
existed as of or any time prior to the Closing;

(d)       the existence prior to the Closing of Hazardous Materials upon, about
or beneath any real property owned, leased or operated by SiTech on -or before
the Closing or migrating or threatening to migrate from such real property, or
the existence of a violation of Environmental Law pertaining to such real
property, regardless of whether the existence of such Hazardous Materials or the
violation of Environmental Law arose prior to the present ownership or operation
of such real property by SiTech or was disclosed to Mentor by SiTech or the
Members;

(e)        all debts, obligations and liabilities of SiTech arising out of,
resulting from or in any manner relating to the Severance Benefits, if any;

(f)        the death of or injury to any person or damage to property that
occurred prior to the Closing and arose out of or in connection with the
business or operations of SiTech (whether asserted, discovered or established
before or after the Closing), and whether or not it is the subject matter of a
claim or action disclosed in the Disclosure Schedule to this Agreement;

(g)        all employment-related claims and causes of action, including,
without limitation, those referenced in the Disclosure Schedule, and all other
claims and causes of action that have arisen or arise out of or in connection
with the operations of the businesses of SiTech conducted prior to the Closing
(whether asserted, discovered or established before or after the Closing); and

(h)        the failure of the transactions contemplated in this Agreement to
Close as a result of SiTech's failure to fulfill its material obligations under
this Agreement that would materially affect the value of SiTech to Mentor.

Damages recoverable hereunder shall exclude any payment amount which Mentor
shall have received under any insurance policy with respect thereto. 
Notwithstanding anything to the contrary in this Agreement, any liability of the
Members under this Section 7.1 is expressly limited to the extent of their
ownership interests in SiTech and any funds received in violation of this
Agreement.

7.2       Indemnification by Mentor. Mentor shall indemnify and hold harmless
the Members, SiTech and SiTech's officers, directors, employees, attorneys,
representatives, successors and assigns in respect of any and all Damages
incurred by, imposed on or borne by SiTech and the Members arising out of,
resulting from or in any manner relating to:

(a)        the breach of any of the representations or warranties made by Mentor
in this Agreement; or

(b)       the breach or the failure of performance by Mentor of any of the
covenants that it is to perform hereunder.

Damages recoverable hereunder shall exclude any payment amount which SiTech-or
the Members shall have received under any insurance policy with respect thereto:

7.3       Indemnification Procedure for Claims. Whenever any claim shall arise
for indemnification hereunder, the party entitled to indemnification (the
"indemnified party") shall promptly notify the other party or parties
(collectively, the "indemnifying party") of the claim and, when known, the facts
constituting the basis for such claim; provided, that the indemnified party's
failure to give such notice shall not affect any rights or remedies of an
indemnified party hereunder with respect to indemnification for Damages except
to the extent that the indemnifying party is materially prejudiced thereby. In
the event of any claim for indemnification hereunder resulting from or in
connection with any claim or legal proceedings by a third party, the notice to
the indemnifying party shall specify, if known, the amount or an estimate of the
amount of the liability arising therefrom. The indemnifying party shall not
settle or compromise any claim by a third party for which it is entitled to
indemnification hereunder, without the prior written consent of the indemnified
party (which shall not be unreasonably withheld) unless suit shall have been
instituted solely against the indemnifying party.

7.4       Defense by Indemnifying Party. In connection with any claim giving
rise to indemnity hereunder or resulting from or arising out of any claim or
legal proceeding by a person who is not a party to this Agreement, the
indemnifying party at its sole cost and expense may, upon written notice to the
indemnified party, assume the defense of any such claim or legal proceeding if
it acknowledges to the indemnified party in writing its obligations to indemnify
the indemnified party with respect to all elements of such claim, and thereafter
diligently conducts the defense thereof with counsel reasonably acceptable to
the indemnified party. The indemnified party shall be entitled to participate in
(but not control) the defense of any such action, with its counsel and at is own
expense.  If the indemnifying party does not assume or fails to conduct in a
diligent manner the defense of any such claim or litigation resulting therefrom,
(i) the indemnified party may defend against such claim or litigation, in such
manner as it may deem appropriate, including, without limitation, settling such
claim or litigation, after giving notice of the same to the indemnifying party,
on such terms as the indemnified party may deem appropriate, and (ii) the
indemnifying party shall be entitled to participate in (but not control) the
defense of such action, with its counsel and it its own expense.  If the
indemnifying party thereafter seeks to question the manner in which the
indemnified party defended such third party claim or the amount or nature of any
such settlement, the indemnifying party shall have the burden to prove by a
preponderance of the evidence that the indemnified party did not defend or
settle such third party claim in a reasonably prudent manner. Each party agrees
to cooperate fully with the other, such cooperation to include, without
limitation, attendance at depositions and the provision of relevant documents as
may be reasonably requested by the indemnifying party; provided, that the
indemnifying party will hold the indemnified party harmless from all of its
expenses, including reasonable attorneys' fees, incurred in connection with such
cooperation by the indemnified party.

7.5       Manner of Indemnification. All indemnification hereunder shall be
effected by payment of cash or delivery of a certified or official bank check to
the indemnified party, or on behalf of such indemnified party to such third
party as the indemnified party may direct, and where Mentor is the indemnified
party, at Mentor's option, by payment from the Holdback.

7.6       Limitations on Indemnification Notwithstanding any provision of this
Agreement to the contrary, SiTech and the Members on the one hand, and Mentor on
the other, shall (i) have no obligation to indemnify any indemnified party
entitled to indemnity under this Article VII unless and until the aggregate
claims for indemnification against such indemnifying party exceed $50,000 (the
"Threshold"), in which event the indemnified party shall be entitled to recover
from the indemnifying party the full cumulative amount thereof and (ii) the
aggregate liability of SiTech and the Members under Section 7.1 shall in no
event exceed the Purchase Price; provided, that notwithstanding the foregoing
the Threshold shall not apply with respect to any of the matters set forth in
Sections 7.1(c), 7.1(d), 7.1(e) or 7.1(f) or any breach of the representations
set forth in Section 3.1 above. Notwithstanding any provision of this. Agreement
to the contrary, the Members shall not be obligated to indemnify Mentor pursuant
to this Article VII with respect to covenants, representations, warranties or
other agreements made by SiTech herein, and shall solely be liable under this
Article VII with respect to and to the extent of the obligations of the Members
as are expressly set forth in this Agreement.

7.7       Survival of Representations and Warranties. All representations and
warranties made by the parties herein or in any instrument or document furnished
in connection herewith shall survive the Closing and (a) the representations and
warranties set forth in Sections 3.1 and 3.2 will continue in full force and
effect in perpetuity, (b) the representations and warranties set forth in
Sections 3.9, 3.10 and 3.14 will survive until the expiration of the respective
statute of limitations with respect to such matters and (c) all other
representations and warranties set forth herein or in any instrument or document
furnished in connection herewith will expire onthe four (4) year anniversary of
the Closing Date. No claim or action for indemnity pursuant to Sections 7.1 or
7.2 hereof for breach of any representation or warranty shall be asserted or
maintained by any party hereto after the expiration of such representation or
warranty pursuant to Section 7.7 except for claims made in writing prior to such
expiration and actions (whether instituted before or after such expiration)
based on any claim made in writing prior to such expiration.  Each party hereto
may rely on the representations and warranties made by the other parties hereto
notwithstanding any investigation of the facts constituting the basis of the
representations and warranties of any party by any other party hereto.

7.8       Payment of Creditors. SiTech will cause SiTechto, pay all debts and
obligations of SiTech in existence on the Closing Date in full on or before the
due date thereof.

ARTICLE VIII
TERMINATION

8.1       Termination. This Agreement may be terminated and the transactions
contemplated herein may be abandoned at any time prior to the Closing:

(a)       by mutual written consent of Mentor and SiTech;

(b)       by Mentor or SiTech if the Closing shall not have occurred on or
before the seven (7) year anniversary of this Agreement; provided (i) that the
right to terminate this Agreement under this Section 8.1(b) shall not be
available to any party whose failure~ to fulfill any of its obligations under
this Agreement has been the cause of, or resulted in, the failure of the Closing
to occur on or before such date; (ii) that if a request for additional
information is received from a governmental authority pursuant to the HSR Act,
such Closing shall be extended to the 90th day following the acknowledgement by
such governmental authority that the parties have complied with such request,
provided that in the event any of the parties litigates the order or injunction
of a governmental authority challenging the transactions contemplated hereby on
antitrust grounds through an appeal, such Closing will be extended through the
completion of such appeal and (iii) that in the event SiTech shall have failed
to meet one of the Milestones set forth on Exhibit B for twelve (12) months or
more, this Agreement shall be automatically renewed for an additional twelve
(12) month period unless Mentor gives written notice of its intention to
terminate the Agreement; and

(c)       by Mentor at any time upon thirty (30) days' prior written notice to
SiTech.

8.2       Effect of Termination. In the event of termination as provided above,
this Agreement shall forthwith become of no further force or effect and, except
as provided in Section 7.1 above, all parties hereto shall bear their own costs
associated with this Agreement and the transactions contemplated hereby;
provided, that Sections 4.7, 9.3, 9.5, 9.11 and 9.12 hereof shall survive such
termination and continue in full force and effect, and such termination ~hal1
not relieve any person of liability for breach of or interference with this
Agreement.

ARTICLE IX
GENERAL PROVISIONS

9.1       Further Assurances.      At the request of any of the parties hereto,
and without further consideration, the other parties agree to execute such
documents and instruments and to do such further acts as may be necessary or
desirable to effectuate the transactions contemplated hereby.

9.2       No Broker or Finder. Each of the parties represents and warrants that
he or it has not dealt with any broker or finder in connection with any of the
transactions contemplated by this Agreement, and, insofar as such party knows,
no broker or other person is entitled to any conversion or finder's fee, in
connection with the transactions contemplated hereby. SiTech and the Members, on
the one hand, and Mentor, on the other, further agree to indemnify and hold
harmless the other against any loss, liability, damage, cost, claim or expense
incurred by reason of any brokerage commission or finder's fee alleged to be
payable because of any act, omission or statement of the indemnifying party.

9.3       Each Party to Bear Own Costs. Each of the parties shall pay all costs
and expenses incurred or to be incurred by such party in negotiating and
preparing this Agreement and the Supply Agreement, and in closing and carrying
out the transactions contemplated by this Agreement and the Supply Agreement.

9.4       Headings. The subject headings of the Articles and Sections of this
Agreement are included for purposes of convenience only, and shall not affect
the construction or interpretation of any of its provisions.

9.5       Entire. Agreement: Waivers. This Agreement (and the Exhibits and
Schedules hereto), the Supply Agreement and the License and Technology Transfer
Agreement (and the Exhibits and Schedules thereto) constitute the entire
agreement among the parties pertaining to the subject matter hereof. No
supplement, modification or amendment of this Agreement shall be binding unless
executed in writing by all parties hereto. No waiver of any of the provisions of
this Agreement shall be deemed, or shall constitute, a waiver of any other
provision, whether or not similar, nor shall any waiver constitute a continuing
waiver. No waiver shall be binding unless executed in writing by the party
making the waiver.

9.6       Third Parties. Nothing in this Agreement, whether express or implied,
is intended to confer any rights or remedies under or by reason of this
Agreement on any persons other than the parties to it and their respective
successors and assigns, nor is anything in this Agreement intended to relieve or
discharge the obligation or liability of any third person to any party to this
Agreement, nor shall any provision give any third persons any right of
subrogation or action over against any party to this Agreement.

9.7       Successors and Assi2ns. This Agreement shall be binding on, and shall
inure to the benefit of, the parties to it and their respective heirs, legal
representatives, successors and assigns. Neither this Agreement nor any right,
interest or obligation hereunder may be assigned by any party hereto without the
prior written consent of the other parties hereto, and any attempt to do so will
be void, except that any party's rights to indemnification under Article 7 may
be freely assigned to any of its Affiliates.

9.8       Consent to Transfer Membership Interests; Obligations of Transferees
and Assigns.  During the term of this Agreement, SiTech will not sell or
transfer any of its assets other than in the ordinary course of business, and
the Members will not voluntarily assign or transfer any interest in their SiTech
Membership Interests without (i) first obtaining the prior written consent of
Mentor (which consent shall not be unreasonably withheld) and (ii) complying
with California law. Additionally, any transferee or assignee to whom SiTech
Membership Interests are transferred or assigned by any Member during the Option
Term, whether voluntarily or by operation of law, shall be subject to all of the
obligations of a Member under this Agreement to the same extent as if such
transferee or assignee shall have agreed in writing to be subject to such
obligations in connection with such transfer or assignment, and SiTech and the
Members will cause such transfer or assignee, as a condition to the
effectiveness of such transfer or assignment, to become a party to this
Agreement and subject to all of the obligations of a Member hereunder.

9.9       Third Party Purchasers. All third party purchasers of the ownership
interests in SiTech including SiTech Membership Interests shall be subjected to
all the obligations and liabilities of the member or Member under this Agreement
from whom such third party purchaser purchased such SiTech Membership Interests,
including without limitation all representations, warranties, covenants and
indemnification obligations of such member or Member.

9.10     Notices. All notices, requests and other communications -hereunder must
be in writing and will be deemed to have been duly given only if delivered
personally against written receipt or by facsimile transmission with answer back
confirmation or mailed (postage prepaid by certified or registered mail, return
receipt requested) or by overnight courier to the parties at the following
addresses or facsimile numbers:

To Mentor:
Chief Legal Counsel
Mentor Corporation
5425 Hollister Avenue
Santa Barbara, California 93111
Facsimile No. (805) 681-6006
Attn:    Douglas H. Altschuler, Esq.

with a copy to:
Brobeck, Phieger & Harrison LLP
550 South Hope Street, 21st Floor
Los Angeles, CA 90071-2604
Facsimile No.: (213) 745-3345
Attn:    V. Joseph Stubbs, Esq.

To SiTech:
Alchemy Engineering, LLC d/b/a SiTech, LLC
c/o Mr. Richard Compton
P.O. Box 1018
Carpentaria, California 93014

To the Members:
Mr. Richard Compton
Mr. Del Petraitis
P.O. Box 1018
Carpentaria, California 93014

All such notices, requests and other communications will (i) if delivered
personally to the address as provided in this Section 9.10, be deemed given upon
delivery, (ii) if delivered by facsimile transmission to the facsimile number as
provided in this Section 9.10, be deemed given upon receipt, and (iii) if
delivered by mail in the manner described above to the address as provided in
this Section 9.10, be deemed given five (5) days after deposit in the United
States mail (in each case regardless of whether such notice, request or other
communication is received by any other person to whom a copy of such notice,
request or other communication is to be delivered pursuant to this Section
9.10). Any party from time to time may change his or its address, facsimile
number or other information for the purpose of notices to that party by giving
notice specifying such change to the other parties hereto.

9.11     Governin2 Law. This Agreement shall be governed by and construed in
accordance with the laws of the State of California applicable to contracts
executed and performed in such State, without giving effect to conflicts of laws
principles.

9.12      Consent to Jurisdiction and Forum Selection. The parties agree that
all actions or proceedings arising in connection with this Agreement shall be
tried and litigated exclusively in the state and federal courts located in the
County of Los Angeles, State of California. Such choice of venue is intended by
the parties to be mandatory and not permissive in nature, thereby precluding the
possibility of litigation between the parties with respect to or arising out of
this Agreement in any jurisdiction other than that specified in this Section
9.12. Each party hereby waives any right it may have to assert the doctrine of
forum non convenes or similar doctrine or to object to venue with respect to any
proceeding brought in accordance with this Section 9.12, and stipulates that the
state and federal courts located in the County of Los Angeles, State of
California shall have in personal jurisdiction and venue over each of them for
the purposes of litigating any dispute, controversy or proceeding arising out of
or related to this Agreement. Each party hereby authorizes and accepts service
of process sufficient for personal jurisdiction in any action against it as
contemplated by this Section 9.12 by registered or certified mail, return
receipt requested, postage prepaid, to its address for the giving of notices as
set forth in this Agreement.. Any final judgment rendered against a party in any
action or proceeding shall be conclusive as to the subject of such final
judgment and may be enforced in other jurisdictions in any manner provided by
law.

9.13     Counterparts. This Agreement may be executed in two (2) or more
counterparts, each of which shall be deemed an original but all of which shall
constitute one and the same instrument.

9.14     Severability. All provisions contained herein are severable and in the
event that any of them shall be held to be to any extent invalid or otherwise
unenforceable by any court of competent jurisdiction, such provision shall be
construed as if it were written so as to effectuate to the greatest possible
extent the parties' expressed intent; and in every case the remainder of this
Agreement shall not be affected thereby and shall remain valid and enforceable,
as if such affected provision were not contained herein.

9.15     Publicity. The parties shall cooperate with each other in the
development and distribution of all news releases and other public disclosures
relating to the transactions contemplated hereby. None of the parties shall
issue or make, or cause to have issued or made, any press release or
announcement concerning the transactions contemplated hereby without the advance
approval in writing of the form and substance thereof by the other parties,
unless otherwise required by applicable law.

9.16     Attorneys' Fees.  If any action at law or in equity is necessary to
enforce or interpret the terms of this agreement, the prevailing party will be
entitled to reasonable attorneys' fees, costs and necessary disbursements in
addition to any other relief to which such party may be entitled.

IN WITNESS WHEREOF, the parties hereto have executed this Option and Asset
Purchase Agreement as of the date first above written.

MENTOR CORPORATION 

By: /S/GARY E. MISTLIN
Name:  Gary E. Mistlin
Its: Vice President of Finance

"Mentor"

ALCHEMY ENGINEERING, LLC
d/b/aSITECH, LLC

By:  /S/RICHARD A. COMPTON
Name:  Richard A. Compton
Its:  President

"SiTech"

/S/RICHARD A. COMPTON

/S/D.J. PETRAITIS

"Members"

 EXHIBIT A
ASSIGNMENT AND ASSUMPTION AGREEMENT

THIS ASSIGNMENT AND ASSUMPTION AGREEMENT (this "Assignment Agreement") is
entered into in connection with that certain Option and Asset Purchase
Agreement, dated as of September __, 1997 (the "Agreement"), by and among MENTOR
CORPORATION, a Minnesota corporation, or its assignee (collectively. "Mentor"),
ALCHEMY ENGINEERING, LLC, a California limited liability company d/b/a SiTech,
LLC ("SiTech"), and Richard A. Compton and Del J. Petraitis, the individual
members of SiTech (such individuals, the "Members"), pursuant to which Mentor
has been granted, and has exercised, an option to buy substantially all of the
assets of SiTech and assume certain liabilities of SiTech. All capitalized terms
used herein and not otherwise defined shall have the meanings ascribed to them
directly or by reference in the Agreement.

WHEREAS, the execution and delivery of this Assignment Agreement is a condition
precedent to the closing of the Agreement;

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, SiTech and Mentor agree as follows:

1.         Liabilities. Subject to the terms and conditions of the Agreement:

(a)        Assumed Liabilities. Subject to Section 1(b) below, Mentor does
hereby agree to assume, pay, fulfill, perform or otherwise discharge SiTech's
liability for (i) post-Closing obligations under the facility and equipment
leases of SiTech as of the date hereof on terms acceptable to Mentor and the
lessorsthereunder; (ii) contracts and accounts payable relating to the purchase
of inventory, sale of products and similar agreements that may arise prior to
the date hereof in the ordinary course of operations of the Business in
accordance with SiTech's prior practice; (iii) SiTech's bank line of credit or
other indebtedness for borrowed money; (iv) all sales and transfer taxes and
fees, if any, generated by the exercise by Mentor of its Option under the
Agreement and its purchase of the Assets thereby and (v) any accrued but unpaid
obligations of SiTech to make distributions under Section 1.6(a) of the
Agreement.

(b)       Excluded Liabilities. Except as expressly set forth in Section 1(a)
above, Mentor shall not and does not hereby assume, pay, perform, defend or
discharge any, and SiTech does and shall hereby solelyretain, pay, perform,
defend and discharge, all of SiTech's liabilitiesand obligations of any and
every kind whatsoever, whether disclosed, undisclosed, direct, indirect,
absolute, contingent, secured, unsecured, accrued or otherwise, whether known or
unknown, including but not limited to: (i) [Intentionally Omitted]; (ii)
specifically excluding the tax obligations described in Section 1 (a)(iv) above,
all income, withholding, or other taxes or fees resulting from the transfer of
the Assets and Business or otherwise; (iii) any obligations or liabilities of
SiTech to its employees, including but not limited to accrued but unpaid
payroll, accrued obligations or liabilities under any employment or consulting
agreements, employee's beneficial interests or options to purchase beneficial
interests in SiTech, employee benefit plans or pension, profit-sharing or
retirement plans or vacation arrangements; (iv) any obligations or liabilities
under the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended
("COBRA"); (v) any liabilities or expenses of SiTech, including brokers',
attorneys' and other professionals' fees incurred in negotiating, executing and
completing SiTech's obligations under the Agreement: (vi) any obligations or
liabilities relating to any products alleged to have been manufactured, or sold
by SiTech and alleged to have been defective, improperly designed or
manufactured or improperly labeled; and (vii) any obligations or liabilities
arising under any Environmental Law (as defined in Section 3.15 of the
Agreement) or any other law (collectively, the "Excluded Liabilities").

2.         No Impact on Agreement. Except as may be expressly provided herein,
the execution of this Assignment Agreement is intended to implement the
provisions of the Agreement without in any manner altering or amending the
provisions thereof.

3.         Further Assurances. SiTech and Mentor further covenant and agree with
such other party hereto that it will, from time to time, at the reasonable
request of such other party, execute and deliver or cause to be executed and
delivered, all such further assignments, assumptions, and other instruments of
transfer and agreements as may be reasonably required by such other party to
more effectively assign to Mentor the liabilities assumed hereby and otherwise
effect the purposes hereof.

4.         Successors and Assigns.~ This Assignment Agreement shall be binding
on, and shall inure to the benefit of, the parties to it and their respective
heirs, legal representatives, successors and assigns.

5.          Counterparts. This Assignment Agreement may be executed in two (2)
or more counterparts, each of which shall be deemed an original but all of which
shall constitute one and the same instrument.

6.         Governing Law. This Assignment Agreement shall be governed by and
construed in accordance with the laws of the State of California applicable to
contracts executed and performed in such State, without giving effect to
conflicts of laws principles.

IN WITNESS WHEREOF, the parties hereto have executed and delivered this
instrument as of the _____ day of __________.

MENTOR CORPORATION
By: /S/GARY E. MISTLIN
Name:  Gary E. Mistlin
Its: Vice President of Finance

"Mentor"

ALCHEMY ENGINEERING, LLC
d/b/aSITECH, LLC

By:  /S/RICHARD A. COMPTON
Name:  Richard A. Compton
Its:  President

"SiTech"

EXHIBIT B
MILESTONES AND PURCHASE PRICE ADJUSTMENT

[*] redacted

EXHIBIT C
ALLOCATION OF PURCHASE PRICE

EXHIBIT D
BILL OF SALE

THIS BILL OF SALE (this "Bill of Sale") is entered into in connection with that
certain Option and Asset Purchase Agreement, dated as of September __, 1997 (the
"Agreement"), by and among MENTOR CORPORATION, a Minnesota corporation, or its
assignee (collectively, "Mentor"), ALCHEMY ENGINEERING, LLC, a California
limited liability company d/b/a SiTech, LLC ("SiTech"), and Richard A. Compton
and Del J. Petraitis, the individual members of SiTech (such individuals, the
"Members"), pursuant to which Mentor has been granted, and has exercised, an
option to buy substantially all of the assets of SiTech. All capitalized terms
used herein and not otherwise defined shall have the meanings ascribed to them
directly or by reference in the Agreement.

WHEREAS, the execution and delivery of this Bill of Sale is a condition
precedent to the closing of the Agreement;

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, SiTech and Mentor agree as follows:

1.         Sale of Assets. Subject to the terms and conditions set forth in the
Agreement, SiTech hereby sells and transfers to Mentor and Mentor hereby
purchases, as a going concern, all of the right, title and interest in and to
all of the tangible and intangible assets owned by SiTech or to which it is
entitled and belonging to or used or intended to be used in the Business, of
every kind and description and wherever located (collectively, the "Assets"), as
of and with effect from the date hereof, upon the terms and conditions set forth
in the Agreement. SiTech hereby represents and warrants that the Assets are
conveyed free and clear of all liabilities, obligations, liens, claims and
encumbrances, except only those liabilities and obligations that are to be
assumed by Mentor as expressly provided in Section 1.4 of the Agreement. From
and after the date hereof, SiTech will have no further right to use, market or
otherwise transfer the Assets.

2.          The Assets. The Assets sold and purchased hereunder, include, but
shall not be limited to:

                                     (i)                   all cash balances of
SiTech;
                                    (ii)                   all of the accounts
receivable of SiTech;

                                   (iii)                   all inventories of
SiTech, including without limitation all raw materials, work in progress,
finished goods (including inventories of finished products held for packaging
and/or shipping and all types of inventories which are in transit or being held
by third parties) and all production, shipping and packaging supplies;

                                   (iv)                   all prepaid expenses,
including deposits and credits of SiTech;

(v)all fixed assets of SiTech, including all machinery, equipment, tools,
handling equipment and accessories and supplies;

                                    (vi)                   all office furniture
and furnishings, equipment and

supplies of SiTech;

(vii)                  all of SiTech 's right, title and interest as tenant in
and to leases and interests in real property (the "Real Property"), together
with all of SiTech's right, title and interest in and to all easements, rights
and appurtenances thereto;

(viii)                 all of SiTech's right, title and interest in and to all
plants, buildings, structures, erections, improvements and fixtures located on
or forming part of the Real Property;

(ix)                   all of SiTech's right, title and interest in, to and
under all domestic and foreign patents, patent applications, patent licenses,
assignable soft*are licenses, assignable know-how licenses and technology
transfer agreements, trade names, trademarks, brand names, logos, copyrights,
unpatented inventions, discoveries, conceptions, reductions to practice, service
marks, trademark and service mark registrations and applications, including
without limitation that certain License and Technology Transfer Agreement (the
"License and Technology Transfer Agreement") between SiTech and NuSil Technology
("NuSil");

(x)                   all of SiTech's right, title and interest in and to trade
secrets, know-how (including, without limitation, proprietary know-how and use
and application know-how) manufacturing, engineering and other drawings,
technology, technical information, engineering data, design and engineering
specifications, formulae, processes, blueprints, sketches, schematics, flow
sheets, flow diagrams, magnetic media such as audio tapes, computer disks,
micromedia such as microfilm and microfiche, promotional literature and similar
data (all rights referred to in 2(ix) and 2(x) together referred to as the
"Intellectual Property");

(xi)                   all of the Business's existing books, general, financial,
tax and personnel records, correspondence and other documents, records and
files, and all data systems and customer information to enable Mentor to
continue the design, manufacture and sale of the Business's products and
services;

(xii)                  the full benefit of all leases of, and conditional sales
contracts and title retention agreements relating to, machinery and equipment of
which SiTech is lessee;

(xiii)                 the full benefit of all contracts or commitments to which
SiTech is entitled, including without limiting the generality of the foregoing,

                        (A)        all unfilled orders received by SiTech; and

7.                     Governing Law. This Bill of Sale shall be governed by and
construed in accordance with the laws of the State of California applicable to
contracts executed and performed in such State, without giving effect to
conflicts of laws principles.

(B)        all forward commitments to SiTech for fixed assets, subleases,
services, inventory, supplies or materials entered into in the usual and
ordinary course of the Business, whether or not there are any written contracts
with respect thereto;

(xiv)                 the full benefit of all licenses, and all registrations
and permits of SiTech pertaining to environmental, health and safety matters,
and all other assignable registrations and permits;

(xv)                  the goodwill of SiTech;

(xvi)                 all computer aided design and other product development
equipment of SiTech; and

(xvii)                all claims, causes of action, rights of recovery, refunds
and rights of set-off of any kind of SiTech, except insofar as necessary to
offset a claim against SiTech but for which SiTech does not recover money. - - -

(xviii) all insurance proceeds and the full benefit of all insurance policies of
SiTech, including without limitation those described in Section 3.12 hereof.

3.         Excluded Assets. Notwithstanding the provisions of Section 2 above to
the contrary, the Assets shall not include:

                                    (i)                    SiTech's minute book,
membership or other ownership

ledger and records and tax records not necessary for Mentor to continue the
Business; and

(ii)                    assets related to employee benefit plans which are not
assumed by Mentor.

4.         No Impact on Agreement. Except as may be expressly provided herein,
the execution of this Bill of Sale is intended to implement the provisions of
the Agreement without in any manner altering or amending the provisions thereof.

5.         Further Assurances. SiTech further covenants and agrees with Mentor
that SiTechwill, from time to time, at the reasonablerequest of Mentor, execute
and deliver or cause to be executed and delivered, all such further bills of
sale, assignments, limited powers or attorney, and other instruments of transfer
and agreements as may be reasonably required by Mentor to more effectively vest
or perfect title in Mentor to the Assets hereby conveyed or intended to be
conveyed.

6.         Successors and Assigns.  This Bill of Sale shall be binding on, and
shall inure to the benefit of, SiTech and Mentor and their respective heirs,
legal representatives, successors and assigns.

IN WITNESS WHEREOF, Mentor and SiTech have executed and delivered this
instrument as of the _________day of __________.

MENTOR CORPORATION
By: /S/GARY E. MISTLIN
Name:  Gary E. Mistlin
Its: Vice President of Finance

"Mentor"

ALCHEMY ENGINEERING, LLC
d/b/aSITECH, LLC
By:  /S/RICHARD A. COMPTON
Name:  Richard A. Compton
Its:  President

"SiTech"

EXHIBIT E
DISCLOSURE SCHEDULE

 3.2      Capitalization. The members of SiTech and their respective interests
are as set forth below:

            Richard A. Compton                           66.6 %
            Del J. Petraitis                                     33.4 %

Capitalization of SiTech has not yet been completed. SiTech has reserved the
right to issue additional membership interests and this schedule will be amended
to reflect the issuance of such interests, the issuance of any non-membership
interests, and any loans or other commitments of funding which shall be deemed
necessary for SiTech to carry out its business purposes.

3.6       Properties.

3.8       Indebtedness.

3.9       Litigation.

3.11     Employees and Service Providers.

3.13     Contracts and Permits.

SiTech has entered into a License and Technology Transfer Agreement with NuSil
Technology dated January 7, 1997 in which SiTech has acquired a license to
certain technology as described therein to enable SiTech to produce certain
silicone materials specifically set forth on Exhibit A to said Agreement in
return for good and valuable consideration as described therein.