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                                                                     Exhibit 4.1

                               FAFCO, INCORPORATED

                                 2002 STOCK PLAN

      1. Purposes of the Plan. The purposes of this 2002 Stock Plan are:

            -     to attract and retain the best available personnel for
                  positions of substantial responsibility,

            -     to provide additional incentive to Employees, Directors and
                  Consultants, and

            -     to promote the success of the Company's business.

            Options granted under the Plan may be Incentive Stock Options or
Nonstatutory Stock Options, as determined by the Administrator at the time of
grant. Stock Purchase Rights may also be granted under the Plan.

      2. Definitions. As used herein, the following definitions shall apply:

            (a) "Administrator" means the Board or any of its Committees as
shall be administering the Plan, in accordance with Section 4 of the Plan.

            (b) "Applicable Laws" means the requirements relating to the
administration of stock option plans under U.S. state corporate laws, U.S.
federal and state securities laws, the Code, any stock exchange or quotation
system on which the Common Stock is listed or quoted and the applicable laws of
any foreign country or jurisdiction where Options or Stock Purchase Rights are,
or will be, granted under the Plan.

            (c) "Board" means the Board of Directors of the Company.

            (d) "Change in Control" means the occurrence of any of the following
events:

                  (i) Any "person" (as such term is used in Sections 13(d) and
14(d) of the Exchange Act) becomes the "beneficial owner" (as defined in Rule
13d-3 of the Exchange Act), directly or indirectly, of securities of the Company
representing fifty percent (50%) or more of the total voting power represented
by the Company's then outstanding voting securities; or

                  (ii) The consummation of the sale or disposition by the
Company of all or substantially all of the Company's assets;

                  (iii) A change in the composition of the Board occurring
within a two-year period, as a result of which fewer than a majority of the
directors are Incumbent Directors. "Incumbent Directors" means directors who
either (A) are Directors as of the effective date of the Plan, or (B) are
elected, or nominated for election, to the Board with the affirmative votes of
at least a majority of the Incumbent Directors at the time of such election or
nomination (but will not include

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an individual whose election or nomination is in connection with an actual or
threatened proxy contest relating to the election of directors to the Company);
or

                     (iv) The consummation of a merger or consolidation of the
Company with any other corporation, other than a merger or consolidation which
would result in the voting securities of the Company outstanding immediately
prior thereto continuing to represent (either by remaining outstanding or by
being converted into voting securities of the surviving entity or its parent) at
least fifty percent (50%) of the total voting power represented by the voting
securities of the Company or such surviving entity or its parent outstanding
immediately after such merger or consolidation.

            (e) "Code" means the Internal Revenue Code of 1986, as amended.

            (f) "Committee" means a committee of Directors appointed by the
Board in accordance with Section 4 of the Plan.

            (g) "Common Stock" means the common stock of the Company.

            (h) "Company" means FAFCO, Incorporated, a California corporation.

            (i) "Consultant" means any natural person, including an advisor,
engaged by the Company or a Parent or Subsidiary to render services to such
entity.

            (j) "Director" means a member of the Board.

            (k) "Employee" means any person, including Officers and Directors,
employed by the Company or any Parent or Subsidiary of the Company. A Service
Provider shall not cease to be an Employee in the case of (i) any leave of
absence approved by the Company or (ii) transfers between locations of the
Company or between the Company, its Parent, any Subsidiary, or any successor.
For purposes of Incentive Stock Options, no such leave may exceed ninety days,
unless reemployment upon expiration of such leave is guaranteed by statute or
contract. If reemployment upon expiration of a leave of absence approved by the
Company is not so guaranteed, then three (3) months following the 91st day of
such leave any Incentive Stock Option held by the Optionee shall cease to be
treated as an Incentive Stock Option and shall be treated for tax purposes as a
Nonstatutory Stock Option. Neither service as a Director nor payment of a
director's fee by the Company shall be sufficient to constitute "employment" by
the Company.

            (l) "Exchange Act" means the Securities Exchange Act of 1934, as
amended.

            (m) "Fair Market Value" means, as of any date, the value of Common
Stock determined as follows:

                  (i) If the Common Stock is listed on any established stock
exchange or a national market system, including without limitation the Nasdaq
National Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its
Fair Market Value shall be the closing sales price for such stock (or the
closing bid, if no sales were reported) as quoted on such exchange or system on
the day of determination, as reported in The Wall Street Journal or such other
source as the Administrator deems reliable;


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                  (ii) If the Common Stock is regularly quoted by a recognized
securities dealer but selling prices are not reported, the Fair Market Value of
a Share of Common Stock shall be the mean between the high bid and low asked
prices for the Common Stock on the day of determination, as reported in The Wall
Street Journal or such other source as the Administrator deems reliable; or

                  (iii) In the absence of an established market for the Common
Stock, the Fair Market Value shall be determined in good faith by the
Administrator.

            (n) "Incentive Stock Option" means an Option intended to qualify as
an incentive stock option within the meaning of Section 422 of the Code and the
regulations promulgated there-under.

            (o) "Nonstatutory Stock Option" means an Option not intended to
qualify as an Incentive Stock Option.

            (p) "Notice of Grant" means a written or electronic notice
evidencing certain terms and conditions of an individual Option or Stock
Purchase Right grant. The Notice of Grant is part of the Option Agreement.

            (q) "Officer" means a person who is an officer of the Company within
the meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

            (r) "Option" means a stock option granted pursuant to the Plan.

            (s) "Option Agreement" means an agreement between the Company and an
Optionee evidencing the terms and conditions of an individual Option grant. The
Option Agreement is subject to the terms and conditions of the Plan.

            (t) "Option Exchange Program" means a program whereby outstanding
Options are surrendered in exchange for Options with a lower exercise price.

            (u) "Optioned Stock" means the Common Stock subject to an Option or
Stock Purchase Right.

            (v) "Optionee" means the holder of an outstanding Option or Stock
Purchase Right granted under the Plan.

            (w) "Parent" means a "parent corporation," whether now or hereafter
existing, as defined in Section 424(e) of the Code.

            (x) "Plan" means this 2002 Stock Plan.

            (y) "Restricted Stock" means shares of Common Stock acquired
pursuant to a grant of Stock Purchase Rights under Section 11 of the Plan.

            (z) "Restricted Stock Purchase Agreement" means a written agreement
between the Company and the Optionee evidencing the terms and restrictions
applying to stock purchased


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under a Stock Purchase Right. The Restricted Stock Purchase Agreement is subject
to the terms and conditions of the Plan and the Notice of Grant.

            (aa) "Rule 16b-3" means Rule 16b-3 of the Exchange Act or any
successor to Rule 16b-3, as in effect when discretion is being exercised with
respect to the Plan.

            (bb) "Section 16(b) " means Section 16(b) of the Exchange Act.

            (cc) "Service Provider" means an Employee, Director or Consultant.

            (dd) "Share" means a share of the Common Stock, as adjusted in
accordance with Section 13 of the Plan.

            (ee) "Stock Purchase Right" means the right to purchase Common Stock
pursuant to Section 11 of the Plan, as evidenced by a Notice of Grant.

            (ff) "Subsidiary" means a "subsidiary corporation", whether now or
hereafter existing, as defined in Section 424(f) of the Code.

      3. Stock Subject to the Plan. Subject to the provisions of Section 13 of
the Plan, the maximum aggregate number of Shares that may be optioned and sold
under the Plan is 500,000 Shares plus an annual increase to be added on the
first day of the Company's fiscal year beginning in 2003, equal to the lesser of
(i) 200,000 shares, (ii) 3% of the outstanding shares on such date or (iii) a
lesser amount determined by the Board. The Shares may be authorized, but
unissued, or reacquired Common Stock.

      Notwithstanding the preceding paragraph, or any other provision of this
Plan, in no event may the number of Shares subject to outstanding options
granted under this Plan, when combined with the number of Shares which are
issuable upon exercise of all other outstanding options, warrants or other
rights granted by the Company to purchase shares of capital stock of the
Company, exceed a number of Shares equal to 30% of the aggregate number of
Shares which are issued and outstanding as of the applicable determination date.

            If an Option or Stock Purchase Right expires or becomes
unexercisable without having been exercised in full, or is surrendered pursuant
to an Option Exchange Program, the unpurchased Shares which were subject thereto
shall become available for future grant or sale under the Plan (unless the Plan
has terminated); provided, however, that Shares that have actually been issued
under the Plan, whether upon exercise of an Option or Right, shall not be
returned to the Plan and shall not become available for future distribution
under the Plan, except that if Shares of Restricted Stock are repurchased by the
Company at their original purchase price, such Shares shall become available for
future grant under the Plan.

      4. Administration of the Plan.

            (a) Procedure.

                  (i) Multiple Administrative Bodies. Different Committees with
respect to different groups of Service Providers may administer the Plan.


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                  (ii) Section 162(m). To the extent that the Administrator
determines it to be desirable to qualify Options granted hereunder as
"performance-based compensation" within the meaning of Section 162(m) of the
Code, the Plan shall be administered by a Committee of two or more "outside
directors" within the meaning of Section 162(m) of the Code.

                  (iii) Rule 16b-3. To the extent desirable to qualify
transactions hereunder as exempt under Rule 16b-3, the transactions contemplated
hereunder shall be structured to satisfy the requirements for exemption under
Rule 16b-3.

                  (iv) Other Administration. Other than as provided above, the
Plan shall be administered by (A) the Board or (B) a Committee, which committee
shall be constituted to satisfy Applicable Laws.

            (b) Powers of the Administrator. Subject to the provisions of the
Plan, and in the case of a Committee, subject to the specific duties delegated
by the Board to such Committee, the Administrator shall have the authority, in
its discretion:

                  (i) to determine the Fair Market Value;

                  (ii) to select the Service Providers to whom Options and Stock
Purchase Rights may be granted hereunder;

                  (iii) to determine the number of shares of Common Stock to be
covered by each Option and Stock Purchase Right granted hereunder;

                  (iv) to approve forms of agreement for use under the Plan;

                  (v) to determine the terms and conditions, not inconsistent
with the terms of the Plan, of any Option or Stock Purchase Right granted
hereunder. Such terms and conditions include, but are not limited to, the
exercise price, the time or times when Options or Stock Purchase Rights may be
exercised (which may be based on performance criteria), any vesting acceleration
or waiver of forfeiture restrictions, and any restriction or limitation
regarding any Option or Stock Purchase Right or the shares of Common Stock
relating thereto, based in each case on such factors as the Administrator, in
its sole discretion, shall determine;

                  (vi) to construe and interpret the terms of the Plan and
awards granted pursuant to the Plan;

                  (vii) to prescribe, amend and rescind rules and regulations
relating to the Plan, including rules and regulations relating to sub-plans
established for the purpose of satisfying applicable foreign laws;

                  (viii) to modify or amend each Option or Stock Purchase Right
(subject to Section 15(c) of the Plan), including the discretionary authority to
extend the post-termination exercisability period of Options longer than is
otherwise provided for in the Plan;

                  (ix) to allow Optionees to satisfy withholding tax obligations
by electing to have the Company withhold from the Shares to be issued upon
exercise of an Option or Stock


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Purchase Right that number of Shares having a Fair Market Value equal to the
minimum amount required to be withheld. The Fair Market Value of the Shares to
be withheld shall be determined on the date that the amount of tax to be
withheld is to be determined. All elections by an Optionee to have Shares
withheld for this purpose shall be made in such form and under such conditions
as the Administrator may deem necessary or advisable;

                  (x) to authorize any person to execute on behalf of the
Company any instrument required to effect the grant of an Option or Stock
Purchase Right previously granted by the Administrator;

                  (xi) to make all other determinations deemed necessary or
advisable for administering the Plan.

            (c) Effect of Administrator's Decision. The Administrator's
decisions, determinations and interpretations shall be final and binding on all
Optionees and any other holders of Options or Stock Purchase Rights.

      5. Eligibility. Nonstatutory Stock Options and Stock Purchase Rights may
be granted to Service Providers. Incentive Stock Options may be granted only to
Employees.

      6. Limitations.

            (a) Each Option shall be designated in the Option Agreement as
either an Incentive Stock Option or a Nonstatutory Stock Option. However,
notwithstanding such designation, to the extent that the aggregate Fair Market
Value of the Shares with respect to which Incentive Stock Options are
exercisable for the first time by the Optionee during any calendar year (under
all plans of the Company and any Parent or Subsidiary) exceeds $100,000, such
Options shall be treated as Nonstatutory Stock Options. For purposes of this
Section 6(a), Incentive Stock Options shall be taken into account in the order
in which they were granted. The Fair Market Value of the Shares shall be
determined as of the time the Option with respect to such Shares is granted.

            (b) Neither the Plan nor any Option or Stock Purchase Right shall
confer upon an Optionee any right with respect to continuing the Optionee's
relationship as a Service Provider with the Company, nor shall they interfere in
any way with the Optionee's right or the Company's right to terminate such
relationship at any time, with or without cause.

            (c) The following limitations shall apply to grants of Options:

                  (i) No Service Provider shall be granted, in any fiscal year
of the Company, Options to purchase more than 200,000 Shares.

                  (ii) In connection with his or her initial service, a Service
Provider may be granted Options to purchase up to an additional 200,000 Shares,
which shall not count against the limit set forth in subsection (i) above.

                  (iii) The foregoing limitations shall be adjusted
proportionately in connection with any change in the Company's capitalization as
described in Section 13.


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                  (iv) If an Option is cancelled in the same fiscal year of the
Company in which it was granted (other than in connection with a transaction
described in Section 13), the cancelled Option will be counted against the
limits set forth in subsections (i) and (ii) above. For this purpose, if the
exercise price of an Option is reduced, the transaction will be treated as a
cancellation of the Option and the grant of a new Option.

      7. Term of Plan. Subject to Section 19 of the Plan, the Plan shall become
effective upon its adoption by the Board. It shall continue in effect for a term
of ten (10) years unless terminated earlier under Section 15 of the Plan.

      8. Term of Option. The term of each Option shall be stated in the Option
Agreement; provided, however, that the term shall be no more than ten (10) years
from the date of grant thereof. Moreover, in the case of an Incentive Stock
Option granted to an Optionee who, at the time the Incentive Stock Option is
granted, owns stock representing more than ten percent (10%) of the total
combined voting power of all classes of stock of the Company or any Parent or
Subsidiary, the term of the Incentive Stock Option shall be five (5) years from
the date of grant or such shorter term as may be provided in the Option
Agreement.

      9. Option Exercise Price and Consideration.

            (a) Exercise Price. The per share exercise price for the Shares to
be issued pursuant to exercise of an Option shall be determined by the
Administrator, subject to the following:

                  (i) In the case of an Incentive Stock Option

                        (A) granted to an Employee who, at the time the
Incentive Stock Option is granted, owns stock representing more than ten percent
(10%) of the voting power of all classes of stock of the Company or any Parent
or Subsidiary, the per Share exercise price shall be no less than 110% of the
Fair Market Value per Share on the date of grant.

                        (B) granted to any Employee other than an Employee
described in paragraph (A) immediately above, the per Share exercise price shall
be no less than 100% of the Fair Market Value per Share on the date of grant.

                  (ii) In the case of a Nonstatutory Stock Option, the per Share
exercise price shall be no less than 85% of the Fair Market Value per Share on
the date of grant. In the case of a Nonstatutory Stock Option intended to
qualify as "performance-based compensation" within the meaning of Section 162(m)
of the Code, the per Share exercise price shall be no less than 100% of the Fair
Market Value per Share on the date of grant.

                  (iii) Notwithstanding the foregoing, Options may be granted
with a per Share exercise price of less than 100% of the Fair Market Value per
Share on the date of grant pursuant to a merger or other corporate transaction.

            (b) Waiting Period and Exercise Dates. Subject to the constraints
herein, at the time an Option is granted, the Administrator shall fix the period
within which the Option may be exercised and shall determine any conditions that
must be satisfied before the Option may be exercised.


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            (c) Form of Consideration. The Administrator shall determine the
acceptable form of consideration for exercising an Option, including the method
of payment. In the case of an Incentive Stock Option, the Administrator shall
determine the acceptable form of consideration at the time of grant. Such
consideration may consist entirely of:

                  (i) cash;

                  (ii) check;

                  (iii) promissory note;

                  (iv) other Shares which, in the case of Shares acquired
directly or indirectly from the Company, (A) have been owned by the Optionee for
more than six (6) months on the date of surrender, and (B) have a Fair Market
Value on the date of surrender equal to the aggregate exercise price of the
Shares as to which said Option shall be exercised;

                  (v) consideration received by the Company under a cashless
exercise program implemented by the Company in connection with the Plan;

                  (vi) a reduction in the amount of any Company liability to the
Optionee, including any liability attributable to the Optionee's participation
in any Company-sponsored deferred compensation program or arrangement;

                  (vii) any combination of the foregoing methods of payment; or

                  (viii) such other consideration and method of payment for the
issuance of Shares to the extent permitted by Applicable Laws.

      10. Exercise of Option.

            (a) Procedure for Exercise; Rights as a Stockholder. Any Option
granted hereunder shall be exercisable according to the terms of the Plan and at
such times and under such conditions as determined by the Administrator and set
forth in the Option Agreement. Unless the Administrator provides otherwise,
vesting of Options granted hereunder shall be suspended during any unpaid leave
of absence. An Option may not be exercised for a fraction of a Share. Except in
the case of Options granted to officers, Directors and Consultants, Options
shall become exercisable at a rate of no less than 20% per year over five (5)
years from the date the Options are granted.

                  An Option shall be deemed exercised when the Company receives:
(i) written or electronic notice of exercise (in accordance with the Option
Agreement) from the person entitled to exercise the Option, and (ii) full
payment for the Shares with respect to which the Option is exercised. Full
payment may consist of any consideration and method of payment authorized by the
Administrator and permitted by the Option Agreement and the Plan. Shares issued
upon exercise of an Option shall be issued in the name of the Optionee or, if
requested by the Optionee, in the name of the Optionee and his or her spouse.
Until the Shares are issued (as evidenced by the appropriate entry on the books
of the Company or of a duly authorized transfer agent of the Company), no right
to vote or receive dividends or any other rights as a stockholder shall exist
with respect to the Optioned Stock, notwithstanding the exercise of the Option.
The Company shall issue (or cause to


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be issued) such Shares promptly after the Option is exercised. No adjustment
will be made for a dividend or other right for which the record date is prior to
the date the Shares are issued, except as provided in Section 13 of the Plan.

                  Exercising an Option in any manner shall decrease the number
of Shares thereafter available, both for purposes of the Plan and for sale under
the Option, by the number of Shares as to which the Option is exercised.

            (b) Termination of Relationship as a Service Provider. If an
Optionee ceases to be a Service Provider, other than upon the Optionee's death
or Disability, the Optionee may exercise his or her Option within thirty (30)
days of termination, or such longer period of time as is specified in the Option
Agreement, to the extent that the Option is vested on the date of termination
(but in no event later than the expiration of the term of such Option as set
forth in the Option Agreement). If, on the date of termination, the Optionee is
not vested as to his or her entire Option, the Shares covered by the unvested
portion of the Option shall revert to the Plan. If, after termination, the
Optionee does not exercise his or her Option within the time specified by the
Administrator, the Option shall terminate, and the Shares covered by such Option
shall revert to the Plan.

            (c) Disability of Optionee. If an Optionee ceases to be a Service
Provider as a result of the Optionee's disability, the Optionee may exercise his
or her Option within six (6) months of termination, or such longer period of
time as is specified in the Option Agreement, to the extent the Option is vested
on the date of termination (but in no event later than the expiration of the
term of such Option as set forth in the Option Agreement). If, on the date of
termination, the Optionee is not vested as to his or her entire Option, the
Shares covered by the unvested portion of the Option shall revert to the Plan.
If, after termination, the Optionee does not exercise his or her Option within
the time specified herein, the Option shall terminate, and the Shares covered by
such Option shall revert to the Plan.

            (d) Death of Optionee. If an Optionee dies while a Service Provider,
the Option may be exercised within six (6) months following the Optionee's
death, or within such longer period of time as is specified in the Option
Agreement, to the extent that the Option is vested on the date of death (but in
no event may the option be exercised later than the expiration of the term of
such Option as set forth in the Option Agreement), by the Optionee's designated
beneficiary, provided such beneficiary has been designated prior to Optionee's
death in a form acceptable to the Administrator. If no such beneficiary has been
designated by the Optionee, then such Option may be exercised by the personal
representative of the Optionee's estate or by the person(s) to whom the Option
is transferred pursuant to the Optionee's will or in accordance with the laws of
descent and distribution. If, at the time of death, Optionee is not vested as to
his or her entire Option, the Shares covered by the unvested portion of the
Option shall immediately revert to the Plan. If the Option is not so exercised
within the time specified herein, the Option shall terminate, and the Shares
covered by such Option shall revert to the Plan.

      11. Stock Purchase Rights.

            (a) Rights to Purchase. Stock Purchase Rights may be issued either
alone, in addition to, or in tandem with other awards granted under the Plan
and/or cash awards made outside of the Plan. After the Administrator determines
that it will offer Stock Purchase Rights under the


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Plan, it shall advise the offeree in writing or electronically, by means of a
Notice of Grant, of the terms, conditions and restrictions related to the offer,
including the number of Shares that the offeree shall be entitled to purchase,
the price to be paid, and the time within which the offeree must accept such
offer. The terms of the offer shall comply in all respects with Section
260.140.42 of Title 10 of the California Code of Regulations. The offer shall be
accepted by execution of a Restricted Stock Purchase Agreement in the form
determined by the Administrator.

            (b) Repurchase Option. Unless the Administrator determines
otherwise, the Restricted Stock Purchase Agreement shall grant the Company a
repurchase option exercisable upon the voluntary or involuntary termination of
the purchaser's service with the Company for any reason (including death or
Disability). The purchase price for Shares repurchased pursuant to the
Restricted Stock Purchase Agreement shall be the original price paid by the
purchaser and may be paid by cancellation of any indebtedness of the purchaser
to the Company. The repurchase option shall lapse at a rate determined by the
Administrator; provided that such rate may not exceed the term permitted under
applicable laws and regulations, including Section 260.140.42 of Title 10 of the
California Code of Regulations.

            (c) Other Provisions. The Restricted Stock Purchase Agreement shall
contain such other terms, provisions and conditions not inconsistent with the
Plan as may be determined by the Administrator in its sole discretion.

            (d) Rights as a Stockholder. Once the Stock Purchase Right is
exercised, the purchaser shall have the rights equivalent to those of a
stockholder, and shall be a stockholder when his or her purchase is entered upon
the records of the duly authorized transfer agent of the Company. No adjustment
will be made for a dividend or other right for which the record date is prior to
the date the Stock Purchase Right is exercised, except as provided in Section 13
of the Plan.

      12. Transferability of Options and Stock Purchase Rights. Unless
determined otherwise by the Administrator, an Option or Stock Purchase Right may
not be sold, pledged, assigned, hypothecated, transferred, or disposed of in any
manner other than by will or by the laws of descent or distribution and may be
exercised, during the lifetime of the Optionee, only by the Optionee. If the
Administrator in its sole discretion makes an Option or Stock Purchase Right
transferable, such Option or Stock Purchase Right may only be transferred (i) by
will, (ii) by the laws of descent and distribution, or (iii) as permitted by
Rule 701 of the Securities Act and by Sections 260.140.41 and 260.140.42 of
Title 10 of the California Code of Regulations.

      13. Adjustments Upon Changes in Capitalization, Merger or Change in
Control.

            (a) Adjustments. In the event that any dividend or other
distribution (whether in the form of cash, Shares, other securities, or other
property), recapitalization, stock split, reverse stock split, reorganization,
merger, consolidation, split-up, spin-off, combination, repurchase, or exchange
of Shares or other securities of the Company, or other change in the corporate
structure of the Company affecting the Shares occurs, the Administrator, in
order to prevent diminution or enlargement of the benefits or potential benefits
intended to be made available under the Plan, may (in its sole discretion)
adjust the number and class of Shares that may be delivered under the Plan
and/or the number, class, and price of Shares covered by each outstanding Option
or Stock Purchase Right.


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            (b) Dissolution or Liquidation. In the event of the proposed
dissolution or liquidation of the Company, the Administrator shall notify each
Optionee as soon as practicable prior to the effective date of such proposed
transaction. The Administrator in its discretion may provide for an Optionee to
have the right to exercise his or her Option until ten (10) days prior to such
transaction as to all of the Optioned Stock covered thereby, including Shares as
to which the Option would not otherwise be exercisable. In addition, the
Administrator may provide that any Company repurchase option applicable to any
Shares purchased upon exercise of an Option or Stock Purchase Right shall lapse
as to all such Shares, provided the proposed dissolution or liquidation takes
place at the time and in the manner contemplated. To the extent it has not been
previously exercised, an Option or Stock Purchase Right will terminate
immediately prior to the consummation of such proposed action.

            (c) Merger or Change in Control. In the event of a merger of the
Company with or into another corporation, or a Change in Control, each
outstanding Option and Stock Purchase Right shall be assumed or an equivalent
option or right substituted by the successor corporation or a Parent or
Subsidiary of the successor corporation. In the event that the successor
corporation refuses to assume or substitute for the Option or Stock Purchase
Right, the Optionee shall fully vest in and have the right to exercise the
Option or Stock Purchase Right as to all of the Optioned Stock, including Shares
as to which it would not otherwise be vested or exercisable. If an Option or
Stock Purchase Right becomes fully vested and exercisable in lieu of assumption
or substitution in the event of a merger or sale of assets, the Administrator
shall notify the Optionee in writing or electronically that the Option or Stock
Purchase Right shall be fully vested and exercisable for a period of fifteen
(15) days from the date of such notice, and the Option or Stock Purchase Right
shall terminate upon the expiration of such period.

                  For the purposes of this subsection (c), the Option or Stock
Purchase Right shall be considered assumed if, following the merger or Change in
Control, the option or right confers the right to purchase or receive, for each
Share of Optioned Stock subject to the Option or Stock Purchase Right
immediately prior to the merger or Change in Control, the consideration (whether
stock, cash, or other securities or property) received in the merger or Change
in Control by holders of Common Stock for each Share held on the effective date
of the transaction (and if holders were offered a choice of consideration, the
type of consideration chosen by the holders of a majority of the outstanding
Shares); provided, however, that if such consideration received in the merger or
Change in Control is not solely common stock of the successor corporation or its
Parent, the Administrator may, with the consent of the successor corporation,
provide for the consideration to be received upon the exercise of the Option or
Stock Purchase Right, for each Share of Optioned Stock subject to the Option or
Stock Purchase Right, to be solely common stock of the successor corporation or
its Parent equal in fair market value to the per share consideration received by
holders of Common Stock in the merger or Change in Control.

      14. Date of Grant. The date of grant of an Option or Stock Purchase Right
shall be, for all purposes, the date on which the Administrator makes the
determination granting such Option or Stock Purchase Right, or such other later
date as is determined by the Administrator. Notice of the determination shall be
provided to each Optionee within a reasonable time after the date of such grant.


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      15. Amendment and Termination of the Plan.

            (a) Amendment and Termination. The Board may at any time amend,
alter, suspend or terminate the Plan.

            (b) Stockholder Approval. The Company shall obtain stockholder
approval of any Plan amendment to the extent necessary and desirable to comply
with Applicable Laws.

            (c) Effect of Amendment or Termination. No amendment, alteration,
suspension or termination of the Plan shall impair the rights of any Optionee,
unless mutually agreed otherwise between the Optionee and the Administrator,
which agreement must be in writing and signed by the Optionee and the Company.
Termination of the Plan shall not affect the Administrator's ability to exercise
the powers granted to it hereunder with respect to Options granted under the
Plan prior to the date of such termination.

      16. Conditions Upon Issuance of Shares.

            (a) Legal Compliance. Shares shall not be issued pursuant to the
exercise of an Option or Stock Purchase Right unless the exercise of such Option
or Stock Purchase Right and the issuance and delivery of such Shares shall
comply with Applicable Laws and shall be further subject to the approval of
counsel for the Company with respect to such compliance.

            (b) Investment Representations. As a condition to the exercise of an
Option or Stock Purchase Right, the Company may require the person exercising
such Option or Stock Purchase Right to represent and warrant at the time of any
such exercise that the Shares are being purchased only for investment and
without any present intention to sell or distribute such Shares if, in the
opinion of counsel for the Company, such a representation is required.

      17. Inability to Obtain Authority. The inability of the Company to obtain
authority from any regulatory body having jurisdiction, which authority is
deemed by the Company's counsel to be necessary to the lawful issuance and sale
of any Shares hereunder, shall relieve the Company of any liability in respect
of the failure to issue or sell such Shares as to which such requisite authority
shall not have been obtained.

      18. Reservation of Shares. The Company, during the term of this Plan, will
at all times reserve and keep available such number of Shares as shall be
sufficient to satisfy the requirements of the Plan.

      19. Stockholder Approval. The Plan shall be subject to approval by the
stockholders of the Company within twelve (12) months after the date the Plan is
adopted. Such stockholder approval shall be obtained in the manner and to the
degree required under Applicable Laws.

      20. Information to Optionees. The Company shall provide to each Optionee
and to each individual who acquires Shares pursuant to the Plan, not less
frequently than annually during the period such Optionee has one or more Options
or Stock Purchase Rights outstanding, and, in the case of an individual who
acquires Shares pursuant to the Plan, during the period such individual owns
such Shares, copies of annual financial statements. The Company shall not be
required to


                                      -12-
<PAGE>
provide such statements to key employees whose duties in connection with the
Company assure their access to equivalent information.


                                      -13-
<PAGE>
                               FAFCO, INCORPORATED

                                 2002 STOCK PLAN

                             STOCK OPTION AGREEMENT

      Unless otherwise defined herein, the terms defined in the 2002 Stock Plan
shall have the same defined meanings in this Stock Option Agreement.

      I. NOTICE OF STOCK OPTION GRANT

      NAME:

      ADDRESS:

      You have been granted an option to purchase Common Stock of the Company,
subject to the terms and conditions of the Plan and this Option Agreement, as
follows:

      Grant Number
                                       --------------------------
      Date of Grant
                                       --------------------------
      Vesting Commencement Date
                                       --------------------------
      Exercise Price per Share         $
                                       --------------------------
      Total Number of Shares Granted
                                       --------------------------
      Total Exercise Price
                                       --------------------------

      Type of Option:                  ___ Incentive Stock Option

                                       ___ Nonstatutory Stock Option

      Term/Expiration Date:
                                       --------------------------
      Vesting Schedule:

      This Option shall be exercisable, in whole or in part, in accordance with
the following schedule:

      [25% of the Shares subject to the Option shall vest twelve months after
the Vesting Commencement Date, and 1/48 of the Shares subject to the Option
shall vest each month thereafter, subject to the Optionee continuing to be a
Service Provider on such dates].

<PAGE>
      Termination Period:

      This Option may be exercised for [three months] after Optionee ceases to
be a Service Provider. Upon the death or Disability of the Optionee, this Option
may be exercised for [twelve months] after Optionee ceases to be a Service
Provider. In no event shall this Option be exercised later than the
Term/Expiration Date as provided above.

      II. AGREEMENT

      A. Grant of Option.

      The Plan Administrator of the Company hereby grants to the Optionee named
in the Notice of Grant attached as Part I of this Agreement (the "Optionee") an
option (the "Option") to purchase the number of Shares, as set forth in the
Notice of Grant, at the exercise price per share set forth in the Notice of
Grant (the "Exercise Price"), subject to the terms and conditions of the Plan,
which is incorporated herein by reference. Subject to Section 15(c) of the Plan,
in the event of a conflict between the terms and conditions of the Plan and the
terms and conditions of this Option Agreement, the terms and conditions of the
Plan shall prevail.

      If designated in the Notice of Grant as an Incentive Stock Option ("ISO"),
this Option is intended to qualify as an Incentive Stock Option under Section
422 of the Code. However, if this Option is intended to be an Incentive Stock
Option, to the extent that it exceeds the $100,000 rule of Code Section 422(d)
it shall be treated as a Nonstatutory Stock Option ("NSO").

      B. Exercise of Option.

      (a) Right to Exercise. This Option is exercisable during its term in
accordance with the Vesting Schedule set out in the Notice of Grant and the
applicable provisions of the Plan and this Option Agreement.

      (b) Method of Exercise. This Option is exercisable by delivery of an
exercise notice, in the form attached as Exhibit A (the "Exercise Notice"),
which shall state the election to exercise the Option, the number of Shares in
respect of which the Option is being exercised (the "Exercised Shares"), and
such other representations and agreements as may be required by the Company
pursuant to the provisions of the Plan. The Exercise Notice shall be completed
by the Optionee and delivered to the Company. The Exercise Notice shall be
accompanied by payment of the aggregate Exercise Price as to all Exercised
Shares. This Option shall be deemed to be exercised upon receipt by the Company
of such fully executed Exercise Notice accompanied by such aggregate Exercise
Price.

      No Shares shall be issued pursuant to the exercise of this Option unless
such issuance and exercise complies with Applicable Laws. Assuming such
compliance, for income tax purposes the Exercised Shares shall be considered
transferred to the Optionee on the date the Option is exercised with respect to
such Exercised Shares.

       C. Method of Payment.


                                      -2-
<PAGE>
      Payment of the aggregate Exercise Price shall be by any of the following,
or a combination thereof, at the election of the Optionee:

      1. cash; or

      2. check; or

      3. consideration received by the Company under a formal cashless exercise
program implemented by the Company in connection with the Plan; or

      4. surrender of other Shares which (i) in the case of Shares acquired
either directly or indirectly from the Company, have been owned by the Optionee
for more than six (6) months on the date of surrender, and (ii) have a Fair
Market Value on the date of surrender equal to the aggregate Exercise Price of
the Exercised Shares.

      D. Non-Transferability of Option.

      This Option may not be transferred in any manner otherwise than by will or
by the laws of descent or distribution and may be exercised during the lifetime
of Optionee only by the Optionee. The terms of the Plan and this Option
Agreement shall be binding upon the executors, administrators, heirs, successors
and assigns of the Optionee.

      E. Term of Option.

      This Option may be exercised only within the term set out in the Notice of
Grant, and may be exercised during such term only in accordance with the Plan
and the terms of this Option Agreement.

      F. Tax Obligations.

      (a) Withholding Taxes. Optionee agrees to make appropriate arrangements
with the Company (or the Parent or Subsidiary employing or retaining Optionee)
for the satisfaction of all Federal, state, local and foreign income and
employment tax withholding requirements applicable to the Option exercise.
Optionee acknowledges and agrees that the Company may refuse to honor the
exercise and refuse to deliver Shares if such withholding amounts are not
delivered at the time of exercise.

      (b) Notice of Disqualifying Disposition of ISO Shares. If the Option
granted to Optionee herein is an ISO, and if Optionee sells or otherwise
disposes of any of the Shares acquired pursuant to the ISO on or before the
later of (1) the date two years after the Date of Grant, or (2) the date one
year after the date of exercise, the Optionee shall immediately notify the
Company in writing of such disposition. Optionee agrees that Optionee may be
subject to income tax withholding by the Company on the compensation income
recognized by the Optionee.

      G. Entire Agreement; Governing Law.

      The Plan is incorporated herein by reference. The Plan and this Option
Agreement constitute the entire agreement of the parties with respect to the
subject matter hereof and supersede in their


                                      -3-
<PAGE>
entirety all prior undertakings and agreements of the Company and Optionee with
respect to the subject matter hereof, and may not be modified adversely to the
Optionee's interest except by means of a writing signed by the Company and
Optionee. This agreement is governed by the internal substantive laws, but not
the choice of law rules, of California.

      H. NO GUARANTEE OF CONTINUED SERVICE.

      OPTIONEE ACKNOWLEDGES AND AGREES THAT THE VESTING OF SHARES PURSUANT TO
THE VESTING SCHEDULE HEREOF IS EARNED ONLY BY CONTINUING AS A SERVICE PROVIDER
AT THE WILL OF THE COMPANY (AND NOT THROUGH THE ACT OF BEING HIRED, BEING
GRANTED AN OPTION OR PURCHASING SHARES HEREUNDER). OPTIONEE FURTHER ACKNOWLEDGES
AND AGREES THAT THIS AGREEMENT, THE TRANSACTIONS CONTEMPLATED HEREUNDER AND THE
VESTING SCHEDULE SET FORTH HEREIN DO NOT CONSTITUTE AN EXPRESS OR IMPLIED
PROMISE OF CONTINUED ENGAGEMENT AS A SERVICE PROVIDER FOR THE VESTING PERIOD,
FOR ANY PERIOD, OR AT ALL, AND SHALL NOT INTERFERE WITH OPTIONEE'S RIGHT OR THE
COMPANY'S RIGHT TO TERMINATE OPTIONEE'S RELATIONSHIP AS A SERVICE PROVIDER AT
ANY TIME, WITH OR WITHOUT CAUSE.

      By Optionee's signature and the signature of the Company's representative
below, Optionee and the Company agree that this Option is granted under and
governed by the terms and conditions of the Plan and this Option Agreement.
Optionee has reviewed the Plan and this Option Agreement in their entirety, has
had an opportunity to obtain the advice of counsel prior to executing this
Option Agreement and fully understands all provisions of the Plan and Option
Agreement. Optionee hereby agrees to accept as binding, conclusive and final all
decisions or interpretations of the Administrator upon any questions relating to
the Plan and Option Agreement. Optionee further agrees to notify the Company
upon any change in the residence address indicated below.

      OPTIONEE:                                 FAFCO, INCORPORATED

      Signature                                 By
                        ---------------------         --------------------------
      Print Name                                Title
                        ---------------------         --------------------------
      Residence Address



                                      -4-
<PAGE>
                               FAFCO, INCORPORATED
                                 2002 STOCK PLAN
                                 EXERCISE NOTICE

      FAFCO, INCORPORATED
      435 Otterson Drive
      Chico, CA 95928-8207
      Attention:  [Title]

      1. Exercise of Option. Effective as of today, ________________, _____, the
undersigned ("Purchaser") hereby elects to purchase ______________ shares (the
"Shares") of the Common Stock of FAFCO, Incorporated (the "Company") under and
pursuant to the 2002 Stock Plan (the "Plan") and the Stock Option Agreement
dated, _____ (the "Option Agreement"). Subject to adjustment in accordance with
Section 13 of the Plan, the purchase price for the Shares shall be $_____, as
required by the Option Agreement.

      2. Delivery of Payment. Purchaser herewith delivers to the Company the
full purchase price for the Shares together with any applicable withholding
taxes.

      3. Representations of Purchaser. Purchaser acknowledges that Purchaser has
received, read and understood the Plan and the Option Agreement and agrees to
abide by and be bound by their terms and conditions.

      4. Rights as Shareholder. Until the issuance (as evidenced by the
appropriate entry on the books of the Company or of a duly authorized transfer
agent of the Company) of the Shares, no right to vote or receive dividends or
any other rights as a shareholder shall exist with respect to the Optioned
Stock, notwithstanding the exercise of the Option. The Shares so acquired shall
be issued to the Optionee as soon as practicable after exercise of the Option.
No adjustment will be made for a dividend or other right for which the record
date is prior to the date of issuance, except as provided in Section 13 of the
Plan.

      5. Tax Consultation. Purchaser understands that Purchaser may suffer
adverse tax consequences as a result of Purchaser's purchase or disposition of
the Shares. Purchaser represents that Purchaser has consulted with any tax
consultants Purchaser deems advisable in connection with the purchase or
disposition of the Shares and that Purchaser is not relying on the Company for
any tax advice.

      6. Entire Agreement; Governing Law. The Plan and Option Agreement are
incorporated herein by reference. This Agreement, the Plan and the Option
Agreement constitute the entire agreement of the parties with respect to the
subject matter hereof and supersede in their entirety all prior undertakings and
agreements of the Company and Purchaser with respect to the subject matter
hereof, and may not be modified adversely to the Purchaser's interest except by
means of a writing signed by the Company and Purchaser. This agreement is
governed by the internal substantive laws, but not the choice of law rules, of
California.


                                      -5-
<PAGE>
      Submitted by:                         Accepted by:

      PURCHASER:                            FAFCO, INCORPORATED

      Signature                             By
                  ----------------------         -------------------------------
      Print Name                            Its
                  ----------------------         -------------------------------
      Address:                              Address:
                                            435 Otterson Drive
                                            Chico, CA 95928-8207

                                            Date Received
                                                          ----------------------

                                      -6-