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                                                                    EXHIBIT 10.4

                      COMMERCIAL LEASE AND DEPOSIT RECEIPT

Received from__Scientific Technologies Incorporated______hereinafter referred to
as LESSEE, the sum of $ 3,193.40(--(Three Thousand One Hundred Ninety Three
Dollars & 40/100________), evidenced by __Check__,as a deposit which shall
belong to Lessor and shall be be applied as follows:

                                                   Total Received Du Prior to
Rent for the period from ___12/01/95___to __12/31/95 $ 1,560.00 $_______ 
$ 12/01/95__
Security deposit (not applicable toward last month's rent)
$ 1,560.00 $_______ $ 12/01/95__
Other _________________Common Area Charge __________  $      73.40 $_______
$ 12/01/96__
Total__________________________________________________  $ 3,193.40 $_______
$___________
                                 In the event that this Lease is not accepted by
the Lessor within 15 days, the total
                                                            deposit received
shall be refunded.

          Lessee offers to lease from Lessor the premises situated in the City
of Menlo Park, County of San Mateo, State of California, described as 1,835
sq.ft. at 3475-G Edison Way as part of a___larger 40,000 Sq.Ft.
Building___________________________upon the following TERMS AND CONDITIONS:

1. TERM:  The term hereof shall commence on__12/01/95________ and end on
   __11/30/96___________
2. RENT:  The total rent shall be $18,720.00 payable as follows: $1,560.00 plus
   $73.40 Common Area charge on the 1st day each month.  All rents shall be
   paid to Lessor or his/her authorized agent, at the following address:

     Ronald M. Newdoll, 3475-A Edison Way, Menlo Park, CA 94025 TEL: (415) 365-
     2843 __________ or at such other places as may be designated by Lessor from
     time to time.  In the event rent is not paid within 10 days after due date,
     Lessee agrees to pay a late charge of $25.00 plus interest at 3% per annum
                                           ------                               
     on the delinquent amount.  Lessee further agrees to pay $ 25.00 for each
     dishonored bank check.  The late charge period is not a grace period, and
     Lessor is entitled to make written demand for any rent if not paid when
     due.
3. USE:  The premises are to be used for the operation of __Electronic Equipment
   Manufacturing, R&D and Related Purposes______and for no other purpose,
   without prior written consent of Lessor.  Lessee shall not commit any waste
   upon the premises, or any nuisance or act which may disturb the quiet
   enjoyment of any tenant in the building.
4. USES PROHIBITED:  Lessee shall not use any portion of the premises for
   purposes other than those specified.  No use shall be made or permitted to be
   made upon the premises, nor acts done, which will increase the existing rate
   of insurance upon the property, or cause cancellation of insurance policies
   covering the property.  Lessee shall not conduct or permit any sale by
   auction on the premises.
5. ASSIGNMENT AND SUBLETTING:  Lessee shall not assign this Lease or sublet any
   portion of the premises without prior written consent of the Lessor, which
   shall not be unreasonably withheld.  Any such assignment or subletting
   without consent shall be void and, at the option of the Lessor shall
   terminate this Lease.
6. ORDINANCES AND STATUTES:  Lessee shall comply with all statutes, ordinances,
   and requirements of all municipal, state and federal authorities now in
   force, or which may later be in force.  The commencement or pendency of any
   state or federal court abatement proceeding affecting the use of the premises
   shall, at the option of the Lessor, be deemed a breach of this Lease.
7. MAINTENANCE, REPAIRS, ALTERATIONS:  Unless otherwise indicated, Lessee
   acknowledges that the premises appear to be in good order and repair.  Lessee
   shall,at his/her own expense,maintain the premises in a good and safe
   condition, including plate glass,  electrical wiring,  plumbing and heating
   installation, and any other system or equipment.   The premises shall be
   surrendered, at termination of the Lease, in as good condition as received,
   normal wear  and tear excepted.  Lessee shall be responsible for all repairs
   required, except the roof, exterior walls, structural foundations,
   and___________________________________________ which shall be maintained by
   Lessor.

     No  improvement or alteration of the premises shall be made without the
     prior written consent of Lessor.  Prior to the commencement of  any
     substantial repair, improvement, or alteration, Lessee shall give Lessor at
     least two (2) days written notice in order that Lessor may post appropriate
     notices to avoid any liability for liens.
8. ENTRY AND INSPECTION:  Lessee shall permit Lessor or Lessor's agents to enter
   the premises at reasonable times and upon reasonable notice for the purpose
   of inspecting the premises, and shall permit Lessor, at any time within sixty
   (60) days prior to the expiration of this Lease, to place upon the premises
   any usual "To Let" or "For Lease" signs, and permit persons desiring to lease
   the premises to inspect the premises at reasonable times.
9. INDEMNIFICATION OF LESSOR:  Lessor shall not be liable for any damage or
   injury to Lessee, or any other person, or to any property, occurring on the
   premises.  Lessee agrees to hold Lessor harmless from any claims for damages
   arising out of Lessee's use of the premises and to indemnify Lessor for any
   expense incurred by Lessor in defending any such claims.
10. POSSESSION:  If Lessor is unable to deliver possession of the premises at
    the commencement date set forth above, Lessor shall not be liable for any
    damage caused by the delay, nor shall this Lease be void or voidable but
    Lessee shall not be liable for any rent until possession is delivered.
    Lessee may terminate this lease if possession is not delivered
    within__15__days of the commencement term in Item 1.

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11. LESSEE'S INSURANCE:  Lessee, at his/her expense, shall maintain plate glass
    and public liability insurance, including bodily injury and property
    damage,insurance Lessee and Lessor with minimum coverage as follows: of
    $500.00.

     Lessee shall provide Lessor with a Certificate of Insurance showing Lessor
  as additional insured.  The  policy shall require ten (10) day's written
  notice to Lessor prior to cancellation or material change of coverage.
12. LESSOR'S INSURANCE:  Lessor shall maintain hazard insurance covering one
    hundred  percent (100%) replacement cost of the improvements throughout the
    Lease term.  Lessor's insurance will not insure Lessee's personal property
    or leasehold improvements.
13. SUBROGATION:  To the maximum extent permitted by insurance policies which
    may be owned by the parties, Lessor and Lessee waive any and all rights of
    subrogation which might otherwise exist.

14  UTILITIES:  Lessee agrees  that he/she shall be responsible  for the payment
  of all utilities including gas, electricity and other services delivered to
  the premises.

15  SIGNS:  Lessor reserves the exclusive right to the roof, side and rear walls
  of  the premises.  Lessee shall not construct any projecting sign or awning
  without the prior written consent of Lessor, which shall not be unreasonably
  withheld.

16  ABANDONMENT OF PREMISES:  Lessee shall not vacate or abandon the premises at
  any time during the term of this Lease.  If Lessee does abandon or vacate the
  premises, or is dispossessed by process of law, or otherwise, any personal
  property belonging to Lessee left on the premises shall be deemed to be
  abandoned, at the option of the Lessor.

17  TRADE FIXTURES:  Any and all improvements made to the premises during the
  term shall belong the Lessor, except trade fixtures of the Lessee.  Lessee
  may, upon termination, remove his/her trade fixtures, but shall pay for all
  costs necessary to repair any damage to the  premises occasioned by the
  removal.

18  DESTRUCTION OF PREMISES:  In the event of a partial destruction of the
  premises during the term, from any cause, Lessor shall promptly repair the
  premises, provided that such repairs can be reasonably made within sixty (60)
  days.  Such partial destruction shall not terminate this Lease, except that
  Lessee shall be entitled to a proportionate reduction of rent while such
  repairs are being made, based upon the extent to which the making of such
  repairs interferes with the business of Lessee on the premises.  If the
  repairs cannot be made within sixty(60) days, this Lease may be terminated at
  the option of either party by giving written notice to  the other party within
  the sixty (60) day period.

19  HAZARDOUS MATERIALS:  Lessee shall not use, store, or dispose of any
  hazardous substances upon the premises, except the use and storage of such
  substances that are customarily used in Lessee's business, and are in
  compliance with all environmental laws.  Hazardous substances means any
  hazardous waste, substance or toxic materials regulated under any
  environmental laws or regulations applicable to the property.

20  INSOLVENCY:  The appointment of a receiver, an assignment for the benefits
  of creditors, or the filing of a petition in bankruptcy by or against Lessee,
  shall constitute a breach of this Lease by Lessee.

21  DEFAULT:  In the event of any breach of this Lease by Lessee, defined as the
  failure to perform any term covenant or condition of lease including payment
  of all sums when due, or cure such failure  within 30 days.  Lessor may, at
              ----         ----                                               
  his/her option, terminate the Lease  and recover from Lessee: (a) the worth at
  the  time of award of the unpaid rent, which had been earned at the time of
  termination;(b) the worth at the time of award of the amount by which the
  unpaid rent which would have been earned after termination until the time of
  the award exceeds the amount of such rental loss that the Lessee proves could
  have reasonably avoided; (c) the worth at the time of award of the amount by
  which the unpaid rent for the balance of the term after the time of award
  exceeds the amount of such rental loss that the Lessee proves could be
  reasonably avoided; and(d) any other amount necessary to compensate Lessor for
  all the detriment proximately caused by the Lessee's failure to perform
  his/her obligations under the Lease or  which in the ordinary course of things
  would be like to result therefrom.

     Lessor may, in the alternative, continue this lease in effect, as long as
  Lessor does not terminate Lessee's right to possession, and Lessor may enforce
  all of Lessor's rights and remedies under the Lease, including the right to
  recover the rent as it becomes due under the Lease.  If said breach of Lease
  continues, Lessor may, at any time thereafter, elect to terminate the Lease.

     Nothing contained herein shall be deemed to limit any other rights or
  remedies which Lessor  may have.
22. SECURITY:  The security deposit set forth above shall secure the performance
    of the Lessee's obligations.  Lessor may, but shall not be obligated to
    apply all or portions of the deposit on account of Lessee's obligations.
    Any balance remaining upon termination  shall be returned to Lessee.  Lessee
    shall not have the right to apply the security  deposit in payment of the
    last month's rent.
23. DEPOSIT REFUNDS: The balance of all deposit shall be refunded within three
    weeks (or otherwise required by law), whichever is sooner from date
    possession is delivered to Lessor of his/her authorized Agent, together with
    a statement showing any charges made against such deposits by Lessor.
24. ATTORNEY'S FEE AND COSTS:  In any section or proceeding involving a dispute
    between Lessor and Lessee arising out of his lease, the prevailing party
    shall be entitled to reasonable attorney's fees.

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24.1 Any dispute arising out of this lease will first be subject to mediation
     if the parties cannot resolve the dispute before litigation.
25. WAIVER:  No failure of Lessor to enforce any term of this Lease shall be
    deemed to be a waiver.
26. NOTICES:  Any notice  which either party may or is required to give, shall
    be given by mailing the same, postage prepaid, to Lessee at the premises, or
    to Lessor at the address shown in item 2, or at such other places as may be
    designated by the parties from time to time.  Notice shall be effective five
    days after mailing, or on personal delivery.
27. HOLDING OVER:  Any holding over after the expiration of this Lease, with the
    consent of Owner, shall become a month-to-month tenancy at a monthly rent of
    $1,560.00 payable in advance and otherwise subject to the terms of this
    Lease, as applicable,  until either party shall terminate the same by giving
    the other party thirty (30) days written notice.
28. TIME:  Time is of the essence of this Lease.
29. HEIRS, ASSIGNS, SUCCESSORS:  This lease is binding upon and inures to the
    benefit of the heirs, assigns and successors of the parties.
30. OPTION TO RENEW:  Provided that Lessee is not  in default in the performance
    of this Lease, Lessee shall have the option to renew the Lease for an
    additional term of 1 Yr plus 3 Yrs option at the conclusion of the first 1
    year option commencing at the expiration of the initial Lease term. All of
    the terms and conditions of the Lease shall apply during the    renewal
    term, except that the monthly rent shall be the same as the current rate.

     The option shall be exercised by written notice given to Lessor not less
  than 60 days prior to the expiration of the initial Lease term.  If notice
  is not given within the time specified, this Option shall expire.
31. AMERICANS WITH DISABILITIES ACT:  The parties are alerted to the existence
    of the Americans With Disabilities Act, which may require costly structural
    modifications.  The parties are advised to consult with a professional
    familiar with the requirements of the Act.
32. LESSOR'S LIABILITY:  In the event of a transfer of Lessor's title or
    interest to the property during the term of this Lease, Lessee agrees that
    the grantee of such title or interest shall be substituted as the Lessor
    under this Lease, and the original Lessor shall be released of all further
    liability; provided, that all deposits shall be transferred to the grantee.
33. ESTOPPEL CERTIFICATE:

  (a) On ten (10) days prior written notice from Lessor, Lessee shall execute,
     acknowledge, and deliver to Lessor a statement in writing:(1) certifying
     that this Lease is unmodified and in full force and effect (or, if
     modified, stating the nature of such modification and certifying that this
     Lease, as so modified, is in full force and effect), the amount of any
     security deposit, and the date to which the rent and other charges are paid
     in advance., if any; and (2) acknowledging that there are not, to Lessee's
     knowledge, any uncured defaults on the part of Lessor, or specifying such
     defaults if any are claimed.  Any such statement may be conclusively relied
     upon by any prospective buyer or encumbrancer of the premises.

  (b) At Lessor's option, Lessee's failure to deliver such statement within such
     time shall be a material breach of this Lease or shall be conclusive upon
     Lessee:(1) that this Lease is in full force and effect, without
     modification except as may be represented by Lessor; (2) that there are no
     uncured defaults in Lessor's performance; and (3) that not more than one
     month's rent has been paid in advance.

  (c) If Lessor desires to finance, refinance, or sell the premises, or any part
     thereof, Lessee agrees to deliver to any lender or buyer designated by
     Lessor such financial statements of Lessee as may be reasonably required by
     such lender or buyer.  All financial statements shall be received by the
     Lessor or the lender or buyer in confidence and shall be used only for the
     purposes set forth

34. ENTIRE AGREEMENT:  The foregoing constitutes the entire Agreement between
    the parties and may be modified only in writing signed by all parties.  The
    following exhibits are a part of this Lease.

  Exhibit A.
  ______________________________________________________________________________
  ____

  The undersigned Lessee hereby acknowledges that he/she has thoroughly read and
approved each of the provisions contained in this Offer, and agrees to the terms
and conditions specified.  Lessee acknowledges receipt of a copy of the accepted
agreements.

  Lessee: s/l Jim Ashford Date:
11/2/95_____Lessee:____________________Date:______________
  Scientific Technologies
  Jim A. Ashford,VP

                                    ACCEPTANCE
The undersigned Lessor accepts the foregoing Offer and agrees to lease the
premises on the terms and conditions set forth above.

NOTICE:  The amount or rate of real estate commissions is not fixed by law.
They are set by each broker individually and may be negotiable between the owner
and broker.

The Lessor agrees to pay to__Blickman and Turkus______, the Broker in this
transaction, the sum of $ 1,123.20 for services rendered.

In any action for commission, the prevailing party shall be entitled to
reasonable attorney fees.

Lessor: s/l Ronald M. Newdoll Date: 11/21/95
Lessor:______________________Date:________________