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                                                                   Exhibit 10.27


                      CUMMINGS PROPERTIES MANAGEMENT, INC.
                                 STANDARD FORM
                                COMMERICAL LEASE                    498233-SMF-A

In consideration of the covenants herein contained, Cummings Properties
Management, Inc., hereinafter called LESSOR, does hereby lease to Wakefield
Engineering, Inc., 60 Audubon Road, Wakefield, MA 01880 hereinafter called
LESSEE, the following described premises, hereinafter called the leased
premises: approximately 19,349 square feet (including 15,4% common area) at 100
Cummings Center, Suite 157H, Beverly, MA 01915 TO HAVE AND HOLD the leased
premises for a term of eight (8) years and six (6) months commencing at noon on
July 1, 1998 and ending at noon on December 31, 2006 unless sooner terminated as
herein provided. LESSOR and LESSEE now covenant and agree that the following
terms and conditions shall govern this lease during the term hereof and for such
further time as LESSEE shall hold the leased premises.

          1. RENT.   LESSEE shall pay to LESSOR base rent at the rate of two
hundred twenty nine thousand forty two (229,042.00)  U.S. dollars per year,
drawn an a  U.S. bank, payable in advance in monthly installments of  $19,086.83
on the first day in each calendar month in advance, the first monthly payment to
be made upon LESSEE's execution of this lease, including payment in advance of
appropriate fractions of a monthly payment for any portion of a month at the
commencement or end of said lease term.  All payments shall be made to LESSOR or
agent at 200 West Cummings Park, Woburn, Massachusetts 01801, or at such other
place as LESSOR shall from time to time in writing designate.  If the "Cost of
Living" has increased as shown by the Consumer Price Index (Boston,
Massachusetts, all items, all urban consumers), U.S. Bureau of Labor Statistics,
the amount of base rent due during each calendar year of this lease and any
extensions thereof shall be annually adjusted in proportion to any increase in
the Index.  All such adjustments shall take place with the rent due on January 1
of each year during the lease term.  The base month from which to determine the
amount of each increase in the Index shall be January 1998, which figure shall
be compared with the figure for November 1998, and each November thereafter to
determine the percentage increase (if any) in the base rent to be paid during
the following calendar year.  In the event that the Consumer Price Index as
presently computed is discontinued as a measure of "Cost of Living" changes, any
adjustment shall then be made on the basis of a comparable index then in general
use.

          2. SECURITY DEPOSIT.   LESSEE shall pay to LESSOR a security deposit
in the amount of nineteen thousand eighty-six and 83/100 ($19,086.83) U.S.
dollars upon the execution of this lease by LESSEE, which shall be held as
security for LESSEE's performance as herein provided and refunded to LESSEE
without interest at the end of this lease, subject to LESSEE's satisfactory
compliance with the conditions hereof.  LESSEE may not apply the security
deposit to payment of the last month's rent.  In the event of any default or
breach of this lease by LESSEE, LESSOR may immediately apply the security
deposit first to any unamortized improvements completed for LESSEE's occupancy,
then to offset any outstanding invoice or other payment due to LESSOR, with the
balance applied to outstanding rent.  If all or any portion of the security
deposit is applied to cure a default or breach during the term of the lease,
LESSEE shall be responsible for restoring said deposit forthwith, and failure to
do so shall be considered a substantial default under the lease.  LESSEE's
failure to remit the full security deposit or any portion thereof when due shall
also constitute a substantial lease default.  Until such time as LESSEE pays the
security deposit and first month's rent, LESSOR may declare this lease null and
void for failure of consideration.

          3. USE OF PREMISES.    LESSEE shall use the leased premises only for
the purpose of  general and administrative offices and prototype research and
development and manufacturing.
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          4. ADDITIONAL RENT.    LESSEE shall pay to LESSOR as additional rent a
proportionate share (based on square footage leased by LESSEE as compared with
the total leaseable square footage of the building of which the leased premises
are a part) of any increase in the real estate taxes levied against the land and
building of which the leased premises are a part (hereinafter called the
building), whether such increase is caused by an increase in the tax rate, or
the assessment on the property, or a change in the method of determining real
estate taxes.  LESSEE shall make payment within thirty (30) days of written
notice from LESSOR that such increased taxes are payable, and any additional
rent shall be prorated should the lease terminate before the end of any tax
year.  The base from which to determine the amount of any increase in taxes
shall be the rate and the assessment in effect as of July 1, 1998.

          5. UTILITIES.    LESSOR shall provide equipment per LESSOR's building
standard specifications to heat the leased premises in season and to cool all
areas between May 1 and November 1.  LESSEE shall pay all charges for utilities
used on the leased premises, including electricity, gas, oil, water and sewer.
LESSEE shall pay the utility provider or LESSOR, as applicable, for all such
utility charges as determined by separate meters serving the leased premises
and/or as a proportionate share of the utility charges for the building if not
separately metered.  LESSEE shall also pay LESSOR  a proportionate share of any
other fees and charges relating in any way to utility use at the building.  No
plumbing, construction or electrical work of any type shall be done without
LESSOR's prior written approval and LESSEE obtaining the appropriate municipal
permit, which shall not be unreasonably withheld or delayed.

          6. COMPLIANCE WITH LAWS.    LESSEE acknowledges that no trade,
occupation, activity or work shall be conducted in the leased premises or use
made thereof which may be unlawful, improper, noisy, offensive, or contrary to
any applicable statute, regulation, ordinance or bylaw.  LESSEE shall keep all
employees working in the leased premises covered by Worker's Compensation
Insurance and shall obtain any licenses and permits necessary for LESSEE's
occupancy.  LESSEE shall be responsible for causing the leased premises and any
alterations by LESSEE which are allowed hereunder to be in full compliance with
any applicable statute, regulation, ordinance or bylaw.

          7. FIRE, CASUALTY, EMINENT DOMAIN.     Should a substantial portion of
the leased premises, or of the property of which they are a part, be
substantially damaged by fire or other casualty, or be taken by eminent domain,
LESSOR may elect to terminate this lease.  When such fire, casualty, or taking
renders the leased premises substantially unsuitable for their intended use, a
just and proportionate abatement of rent shall be made, and LESSEE may elect to
terminate this lease if: (a) LESSOR fails to give written notice within thirty
(30) days of intention to restore the leased premises, or (b) LESSOR fails to
restore the leased premises to a condition substantially suitable for their
intended use within ninety (90) days of said fire, casualty or taking.  LESSOR
reserves all rights for damages or injury to the leased premises for any taking
by eminent domain, except for damage to LESSEE's property or equipment.

          8. FIRE INSURANCE.     LESSEE shall not permit any use of the leased
premises which will adversely affect or make voidable any insurance on the
property of which the leased premises are a part, or on the contents of said
property, or which shall be contrary to any law or regulation from time to time
established by the Insurance Services Office (or successor), local Fire
Department, LESSOR's insurer, or any similar body.  LESSEE shall on demand
reimburse LESSOR, and all other tenants, all extra insurance premiums caused by
LESSEE's use of the leased premises.  LESSEE shall not vacate the leased
premises or permit same to be unoccupied other than during LESSEE's customary
non-business days or hours.

          9. MAINTENANCE OF PREMISES.    LESSOR will be responsible for all
structural maintenance of the leased premises and for the normal daytime
maintenance of all space heating and cooling equipment, sprinklers, doors,
locks, plumbing, and electrical wiring, but specifically excluding damage caused
by the careless, malicious, willful, or negligent acts of LESSEE or others,
chemical, water or corrosion damage from any source, and maintenance of any non
"building standard" leasehold improvements.  LESSEE agrees to maintain at its
expense all other aspects of the leased premises in the same condition as they
are at the commencement of the term or as they may be put in during the term of
this lease, normal wear and tear and damage by fire or other casualty only
excepted, and whenever necessary, to replace light bulbs, plate glass and other
glass therein, acknowledging that the leased premises are now in good order 
<PAGE>
 
and the light bulbs and glass whole. LESSEE will properly control or vent all
solvents, degreasers, smoke, odors, etc. and shall not cause the area
surrounding the leased premises to be in anything other than a neat and clean
condition, depositing all waste in appropriate receptacles. LESSEE shall be
solely responsible for any damage to plumbing equipment, sanitary lines, or any
other portion of the building which results from the discharge or use of any
acid or corrosive substance by LESSEE. LESSEE shall not permit the leased
premises to be overloaded, damaged, stripped or defaced, nor suffer any waste,
and will not keep animal within the leased premises. If the leased premises
include any wooden mezzanine type space, the floor capacity of such space is
suitable only for office use, light storage or assembly work. LESSEE will
protect any carpet with plastic or masonite chair pads under any roiling chairs.
Unless heat is provided at LESSOR's expense, LESSEE shall maintain sufficient
heat to prevent freezing of pipes or other damage. Any increase in air
conditioning equipment or electrical capacity or any installation or maintenance
of equipment which is necessitated by some specific aspect of LESSEE's use of
the leased premises shall be LESSEE's sole responsibility, at LESSEE's expense
and subject to LESSOR's prior written consent. All maintenance provided by
LESSOR shall be during LESSOR's normal business hours.

          10. ALTERATIONS.  LESSEE shall not make structural alterations or
additions of any kind to the leased premises, but may make nonstructural
alterations provided LESSOR  consents thereto in writing.  All such allowed
alterations shall be at LESSEE's expense and shall conform with LESSOR's
construction specifications.  If LESSOR or LESSOR's agent provides any services
or maintenance for LESSEE in connection with such alterations or otherwise under
this lease, any just invoice will be promptly paid.  LESSSEE shall not permit
any mechanics' liens, or similar liens, to remain upon the leased premises in
connection with work of any character performed or claimed to have been
performed at the direction of LESSEE and shall cause any such lien to be
released or removed forthwith without cost to LESSOR.  Any alterations or
additions shall become part of the leased premises and the property of LESSOR.
Any alterations completed by LESSOR or LESSEE shall be LESSOR's "building
standard" unless noted otherwise.  LESSOR shall have the right at any time to
change the arrangement of parking areas, stairs, walkways or other common areas
of the building.

          11. ASSIGNMENT OR SUBLEASING.     LESSEE shall not assign this lease
or sublet or allow any other firm or individual to occupy the whole or any part
of the leased premises without LESSOR's prior written consent.  Notwithstanding
such assignment or subleasing, LESSEE and GUARANTOR shall remain liable to
LESSOR for the payment of all rent and for the full performance of the covenants
and conditions of this lease.  LESSEE shall pay LESSOR promptly for legal and
administrative expenses incurred by LESSOR in connection with any consent
requested hereunder by LESSEE.

          12. SUBORDINATION.    This lease shall be subject and subordinate to
any and all mortgages and other instruments in the nature of a mortgage, now or
at any time hereafter, and LESSEE shall, when requested, promptly execute and
deliver such written instruments as shall be necessary to show the subordination
of this lease to said mortgages or other such instruments in the nature of a
mortgage.

          13. LESSOR'S ACCESS.    LESSOR or agents of LESSOR may at any
reasonable time enter to view the leased premises, to make repairs and
alterations as LESSOR should elect to do for the leased premises, the common
areas or any other portions of the building, to make repairs which LESSEE is
required but has failed to do, and to show the leased premises to others.

          14. SNOW REMOVAL.    The plowing of snow from all roadways and
unobstructed parking areas shall be at the sole expense of LESSOR.  The control
of snow and ice on all walkways, steps and loading areas serving the leased
premises and all other areas not readily accessible to plows shall be the sole
responsibility of LESSEE.  Notwithstanding the foregoing, however, LESSEE shall
hold LESSOR and OWNER harmless from any and all claims by LESSEE's agents,
representatives, employees, callers or invitees for damage or personal injury
resulting in any way from snow or ice on any area serving the leased premises.
<PAGE>
 
          15. ACCESS AND PARKING.   LESSEE shall have the right without
additional charge to use parking facilities provided for the leased premises in
common with others entitled to the use thereof.  Said parking areas plus any
stairs, corridors, walkways, elevators or other common areas (hereinafter
collectively called the common areas) shall in all cases be considered a part of
the leased premises when they are used by LESSEE or LESSEE's employees, agents,
callers or invitees.  LESSEE will not obstruct in any manner any portion of the
building or the walkways or approaches to the building, and will conform to all
rules and regulations now or hereafter made by LESSOR for parking, and for the
care, use, or alteration of the building, its facilities and approaches.  LESSEE
further warrants that LESSEE will not permit any employee or visitor to violate
this or any other covenant or obligation of LESSEE.  No unattended parking will
be permitted between 7:00 PM and 7:00 AM without LESSOR's prior written
approval, and from December 1 through March 31 annually, such parking shall be
permitted only in those areas specifically designated for assigned overnight
parking.  Unregistered or disabled vehicles, or storage trailers of any type,
may not be parked at any time.  LESSOR may tow, at LESSEE's sole risk and
expense, any misparked vehicle belonging to LESSEE or LESSEE's agents,
employees, invitees or callers, at any time.  LESSOR shall not be responsible
for providing any security services for the leased premises.

          16. LIABILITY.    LESSEE shall be solely responsible as between LESSOR
and LESSEE for deaths or personal injuries to all persons whomsoever occurring
in or on the leased premises (including any common areas that are considered
part of the leased premises hereunder) from whatever cause arising, and damage
to property to whomsoever belonging arising out of the use, control, condition
or occupation of the leased premises by LESSEE; and LESSEE agrees to indemnify
and save harmless LESSOR and OWNER from any and all liability, including but not
limited to costs, expenses, damages, causes of action, claims, judgments and
attorney's fees caused by or in any way growing out of any matters aforesaid,
except for death, personal injuries or property damage directly resulting from
the willful misconduct, recklessness or gross negligence of LESSOR, or its
employees.

          17. INSURANCE.     LESSEE will secure and carry at its own expense a
commercial general liability policy insuring LESSEE, LESSOR, and OWNER against
any claims based on bodily injury (including death) or property damage arising
out of the condition of the leased premises (including any common areas that are
considered part of the leased premises hereunder) or their use by LESSEE, such
policy to insure LESSEE, LESSOR and OWNER against any claim up to One Million
($1,000,000.00) Dollars in the case of any one accident involving bodily injury
(including death), and up to One Million ($1,000,000.00) Dollars against any
claim for damage to property.  LESSOR and OWNER shall be included in each such
policy as additional insureds using ISO Form CG 20 26 11 85 or some other form
approved by LESSOR.  LESSEE will file with LESSOR prior to occupancy
certificates and any applicable riders or endorsements showing that such
insurance is in force, and thereafter will file renewal certificates prior to
the expiration of any such policies.  All such insurance certificates shall
provide that such policies shall not be cancelled without at least ten (10) days
prior written notice to each insured.  In the event LESSEE  shall fail to
provide or maintain such insurance at any time during the term of this lease,
then LESSOR may elect to contract for such insurance at LESSEE's expense.

          18. SIGNS.    LESSOR authorizes, and LESSEE at LESSEE's expense agrees
to erect promptly upon commencement of this lease, signage for the leased
premises in accordance with LESSOR's building standards for style, size,
location, etc.  LESSEE shall obtain the prior written consent of LESSOR before
erecting any sign on the leased premises, which consent shall include approval
as to size, wording, design and location.  LESSOR may remove and dispose of any
sign not approved, erected or displayed in conformance with this lease.

          19. BROKERAGE.      LESSEE warrants and represents to LESSOR that
LESSEE has dealt with no broker or third person with respect to this lease, and
LESSEE agrees to indemnify LESSOR against any brokerage claims arising by virtue
of this lease.  LESSOR warrants and represents to LESSEE that LESSOR has
employed no exclusive broker or agent in connection with the letting of the
leased premises.
<PAGE>
 
          20. DEFAULT AND ACCELERATION OF RENT.   In the event that: (a) any
assignment for the benefit of creditors, trust mortgage, receivership or other
insolvency proceeding shall be made or instituted with respect to LESSEE or
LESSEE's property; (b) LESSEE shall default in the observance or performance of
any of LESSEE's covenants, agreements, or obligations hereunder, other than
substantial monetary payments as provided below, and such default shall not be
corrected within ten (10) days after written notice thereof; or (c) LESSEE
vacates the leased premises, then LESSOR shall have the right thereafter, while
such default continues and without demand or further notice, to re-enter and
take possession of the leased premises, to declare the term of this lease ended,
and to remove LESSEE's effects, without being guilty of any manner of trespass,
and without prejudice to any remedies which might be otherwise used for arrears
of rent or other default or breach of the lease.  If LESSEE shall default in the
payment of the security deposit, rent, taxes, substantial invoice from LESSOR or
LESSOR's agent for goods and/or services or other sum herein specified, and such
default shall continue for ten (10) days after written notice thereof, and ,
because both parties agree that nonpayment of said sums when due is a
substantial breach of the lease, and because the payment of rent in monthly
installments is for the sole benefit and convenience of LESSEE, then in addition
to the foregoing remedies the entire balance of rent which is due hereunder
shall become immediately due and payable as liquidated damages.  LESSOR, without
being under any obligation to do so and without thereby waiving any default, may
remedy same for the account and at the expense of LESSEE.  If LESSOR pays or
incurs any obligations for the payment of money in connection therewith, such
sums paid or obligations incurred plus interest and costs, shall be paid to
LESSOR by LESSEE as additional rent.  Any sums received by LESSOR from or on
behalf of LESSEE at any time shall be applied first to any unamortized
improvements completed for LESSEE's occupancy, then to offset any outstanding
invoice or other payment due to LESSOR, with the balance applied to outstanding
rent.  LESSEE agrees to pay reasonable attorney's fees and/or administrative
costs incurred by LESSOR in enforcing any or all obligations of LESSEE under
this lease at any time LESSEE shall pay LESSOR interest at the rate of fifteen
(15) percent per annum on any payment from LESSEE to LESSOR which is past due.

          21. NOTICE.  Any notice from LESSOR to LESSEE relating to the leased
premises or to the occupancy thereof shall be deemed duly served when left at
the leased premises addressed to LESSEE, or served by constable, or sent to the
leased premises by certified mail, return receipt requested, postage prepaid,
addressed to LESSEE, Attn:  President.  Any notice from LESSEE to LESSOR
relating to the leased premises or to the occupancy thereof shall be deemed duly
served when served by constable, or delivered to LESSOR by certified mail,
return receipt requested, postage prepaid, addressed to LESSOR at 200 West
Cummings Park, Woburn, MA 01801 or at LESSOR's last designated address. No oral
notice or representation shall have any force or effect. Time is of the essence
in the service of any notice.

          22. OCCUPANCY.     In the event that LESSEE takes possession of said
leased premises prior to the start of the lease term, LESSEE will perform and
observe all of LESSEE's covenants from the date upon which LESSEE takes
possession except the obligation for the payment of extra rent for any period of
less than one month.  LESSEE shall not remove LESSEE's goods or property from
the leased premises other than in the ordinary and usual course of business,
without having first paid and satisfied LESSOR for all rent which may become due
during the entire term of this lease.  LESSOR may require LESSEE to relocate to
another similar ground floor (or other if acceptable to LESSEE) facility at
Cummings Center no more than one time during the term of the lease upon prior
written notice to LESSEE and on terms comparable to those herein.  In the event
that LESSEE continues to occupy or control all or any part of the leased
premises after the agreed termination of this lease without the written
permission of LESSOR, then LESSEE shall be liable to LESSOR for any and all
loss, damages or expenses incurred by LESSOR, and all other terms of this lease
shall continue to apply except that rent shall be due in full monthly
installments at a rate of one hundred fifty (150) percent of that which would
otherwise be due under this lease, it being understood between the parties that
such extended occupancy is as a tenant at sufferance and is solely for the
benefit and convenience of LESSEE and as such has greater rental value.
LESSEE's  control  or  occupancy  of  all  or any  part  of  the leased
premises  beyond  noon on the last day  of  any  monthly  rental  period  shall
constitute  LESSEE's occupancy for an entire month, and increased  rent  as
provided  in  this  section shall  be due and  payable  immediately in advance.
<PAGE>
 
LESSOR's acceptance of any payments from LESSEE during such extended occupancy
shall not alter LESSEE's status as a tenant at sufferance.

          23. FIRE PREVENTION.  LESSEE agrees to use every reasonable precaution
against fire and agrees to provide and maintain approved, labeled fire
extinguishers, emergency lighting equipment, and exit signs and complete any
other modifications within the leased premises as required or recommended by the
Insurance Services Office (or successor organization), OSHA, the local Fire
Department, or any similar body.

          24. OUTSIDE AREA.    Any goods, equipment, or things of any type or
description held or stored in any common area without LESSOR's prior written
consent shall be deemed abandoned and may be removed by LESSOR at LESSEE's
expense without notice.  LESSEE shall maintain a building standard size dumpster
in a location approved by LESSOR, which dumpster shall be provided and serviced
at LESSEE's expense by whichever disposal firm may from time to time be
designated by LESSOR. Alternately, if a shared dumpster or compactor is provided
by LESSOR, LESSEE shall pay its proportionate share of any costs associated
therewith.

          25. ENVIRONMENT.  LESSEE will so conduct and operate the leased
premises as not to interfere in any way with the use and enjoyment of other
portions of the same or neighboring buildings by others by reason of odors,
smoke, exhaust, smells, noise, pets, accumulation of garbage or trash, vermin or
other pests, or otherwise, and will at its expense employ a professional pest
control service if necessary. LESSEE agrees to maintain efficient and effective
devices for preventing damage to hearing equipment from solvents, degreasers,
cutting oils, propellants, etc. which may be present at the leased premises.  No
hazardous materials or wastes shall be stored, disposed of, or allowed to remain
at the leased premises at any time, and LESSEE shall be solely responsible for
any and all corrosion or other damage associated with the use, storage and/or
disposal of same by LESSEE.

          26. RESPONSIBILITY.      Neither LESSOR nor OWNER shall be held liable
to anyone for loss or damage caused in any way by the use, leakage, seepage or
escape of water from any source, or for the cessation of any service rendered
customarily to said premises or buildings, or agreed to by the terms of this
lease, due to any accident, the making of repairs, alterations or improvements,
labor difficulties, weather conditions, mechanical breakdowns, trouble or
scarcity in obtaining fuel, electricity, service or supplies from the sources
from which they are usually obtained for said building, or any cause beyond
LESSOR's immediate control.

          27. SURRENDER.     LESSEE shall at the termination of this lease
remove all of LESSEE's goods and effects from the leased premises.  LESSEE shall
deliver to LESSOR the leased premises and all keys and locks thereto, all
fixtures and equipment connected therewith, and all alterations, additions and
improvements made to or upon the leased premises, whether completed by LESSEE,
LESSOR or others, including but not limited any offices, partitions, window
blinds, floor coverings (including computer floors), plumbing and plumbing
fixtures, air conditioning equipment and ductwork of any type, exhaust fans or
heaters, water coolers, burglar alarms, telephone wiring, air or gas
distribution piping, compressors, overhead cranes, hoists, trolleys or
conveyors, counters, shelving or signs attached to walls or floors, all
electrical work, including but not limited to lighting fixtures of any type,
wiring conduit, EMT, transformers, distribution panels, bus ducts, raceways,
outlets and disconnects, and furnishings or equipment which have been bolted,
welded, nailed, screwed, glued or otherwise attached to any wall, floor ceiling,
roof, pavement or ground, or which have been directly wired to any portion of
the electrical system or which have been plumbed to the water supply, drainage
or venting systems serving the lease premises. LESSEE shall deliver the leased
premises sanitized from any chemicals or other contaminants, and broom clean and
in the same condition as they were at the commencement of this lease or any
prior lease between the parties for the leased premises, or as they were
modified during said term with LESSOR's written consent, reasonable wear and
tear and damage by fire or other casualty only excepted. In the event of
LESSEE's failure to remove any of LESSEE's property from the leased premises
upon termination of the lease, LESSOR is hereby authorized, without liability to
LESSEE for loss or damage thereto, and at the sole risk of LESSEE, to remove and
store any such property at LESSEE's expense, or to retain same under LESSOR's
control, or to sell at public or private sale (without 
<PAGE>
 
notice), any or all of the property not so removed and to apply the net proceeds
of such sale to the payment of any sum due hereunder, or to destroy such
abandoned property. In no case shall the leased premises by deemed surrendered
to LESSOR until the termination date provided herein or such other date as may
be specified in a written agreement between the parties, notwithstanding the
delivery of any keys to LESSOR.

          28. GENERAL.    (a) The invalidity or unenforceablilty of any
provision of this lease shall not affect or render invalid or unenforceable any
other provision hereof.  (b) The obligations of this lease shall run with the
land, and this lease shall be binding upon and inure to the benefit of the
parties hereto and their respective successors and assigns, except that LESSOR
and OWNER shall be liable only for obligations occurring while lessor, owner, or
master lessee of the premises.  (c) Any action or proceeding arising out of the
subject matter of this lease shall be brought by LESSEE within one year after
the cause of action has occurred and only in a court of the Commonwealth of
Massachusetts.  (d) If LESSOR is acting under or as agent for any trust or
corporation the obligations of LESSOR shall be binding upon the trust or
corporation, but not upon any trustee, officer, director, shareholder, or
beneficiary of the trust or corporation individually.  (e) If LESSOR is not the
owner (OWNER) of the leased premises, LESSOR represents that said OWNER has
agreed to be bound by the terms of this lease unless LESSEE is in default
hereof.  (f) This lease is made and delivered in the Commonwealth of
Massachusetts, and shall be interpreted, construed, and enforced in accordance
with the laws thereof.  (g) This lease was the result of negotiations between
parties of equal bargaining strength, and when executed by both parties shall
constitute the entire agreement between the parties, superseding all prior oral
and written agreements, representations, statements and negotiations relating in
any way to the subject matter herein.  This lease may not be extended or amended
except by written agreement signed by both parties or as otherwise provided
herein, and no other subsequent oral or written representation shall have any
effect hereon.  (h) Notwithstanding any other statements herein, LESSOR makes no
warranty, express or implied, concerning the suitability of the leased premises
for LESSEE's intended use.  (i) LESSEE agrees that if LESSOR does not deliver
possession of the leased premises as herein provided for any reason, LESSOR
shall not be liable for any damages to LESSEE for such failure, but LESSOR
agrees to use reasonable efforts to deliver possession to LESSEE at the earliest
possible date.  A proportionate abatement of rent, excluding the cost of any
amortized improvements to the leased premises, for such time as LESSEE may be
deprived of possession of the leased premises, except where a delay in delivery
is caused in any way by LESSEE, shall be LESSEE's sole remedy.  (j) Neither the
submission of this lease form, not the prospective acceptance of the security
deposit and/or rent shall constitute a reservation of or option for the leased
premises, or an offer to lease, it being expressly understood and agreed that
this lease shall not bind either party in any manner whatsoever until it has
been executed by both parties.  (k) LESSEE shall not be entitled to exercise any
option contained herein if LESSEE is at that time in default of any terms or
conditions hereof.  (l) Except as otherwise provided herein, LESSOR, OWNER, and
LESSEE shall not be liable for any special incidental, indirect or consequential
damages, including but not limited to lost profits or loss of business, arising
out of or in any manner connected with performance or nonperformance under this
lease, even if any party has knowledge of the possibility of such damages.  (m)
The headings in this lease are for convenience only and shall not be considered
part of the terms hereof.  (n) No endorsement by LESSEE on any check shall bind
LESSOR in any way.  (o) LESSOR and LESSEE hereby waive any and all rights to a
jury trial in any proceedings in any way arising out of this lease.

          29. SECURITY AGREEMENT. (THIS PARAGRAPH DOES NOT APPLY)

          30. WAIVERS, ETC.  No consent or waiver, express or implied, by
LESSOR, to or of any breach of any covenant, condition or duty of LESSEE shall
be construed as a consent or waiver to or of any breach of the same or any other
covenant, condition or duty. If LESSEE is several persons, several corporations
or a partnership, LESSEE's obligations are joint or partnership and also
several. Unless repugnant to the context, "LESSOR" and "LESSEE" mean the person
or persons, natural or corporate, named above as LESSOR and as LESSEE
respectively, and their respective heirs, executors, administrators, successors
and assigns.
<PAGE>
 
          31. AUTOMATIC FIVE-YEAR EXTENSIONS.    This lease, including all
terms, conditions, escalations, etc. shall be automatically extended for
additional successive periods of five (5) years each unless LESSOR or LESSEE
shall serve written notice, either party to the other, of either party's desire
not to so extend the lease.  The time for serving such written notice shall be
not more than twelve (12) months or less than six (6) months prior to the
expiration of the then current lease period.  Time is of the essence.

          32. ADDITIONAL PROVISIONS. (Continued on attached rider(s) if
necessary.)



                             - See attached Rider



  IN WITNESS WHEREOF, LESSOR and LESSEE have hereunto set their hands and common
seals and intend to be legally bound hereby this 30 day of April , 1998.

LESSOR:  CUMMINGS PROPERTIES MANAGEMENT, INC.   LESSEE:  WAKEFIELD ENGINEERING,
INC.

 By:                                            By:   /s/ Michael Hoffmann
     ------------------------------------          -----------------------------
                                President



                                   GUARANTY

IN CONSIDERATION of the making of the above lease by Cummings Properties
Management, Inc. with Wakefield Engineering, Inc.   at the request of the
undersigned and in reliance on this guaranty, the undersigned (GUARANTOR) hereby
personally guarantees the prompt payment of rent by LESSEE and the performance
by LESSEE of all terms, conditions, covenants and agreements of the lease, any
amendments thereto and any extensions or assignments thereof, and the
undersigned promises to pay all expenses, including reasonable attorney's fees,
incurred by LESSOR in enforcing all obligations of LESSEE under the lease or
incurred by LESSOR in enforcing this guaranty.  LESSOR'S consent to any
assignments, subleases, amendments and extensions by LESSEE or to any compromise
or release of LESSEE'S liability hereunder, with or without notice to the
undersigned, or LESSOR'S failure to notify the undersigned of any default and/or
reinstatement of the lease by LESSEE, shall not relieve the undersigned from
liability as GUARANTOR.

IN WITNESS WHEREOF, the undersigned GUARANTOR has hereunto set his/her/its hand
and common seal intending to be legally bound hereby as of this    day of     
         ,    .
<PAGE>
 
                      CUMMINGS PROPERTIES MANAGEMENT, INC.
                                STANDARD FORM                     498233-SMF-6
                                RIDER TO LEASE

The following additional provisions are incorporated into and made a part of the
attached lease:

  A.  UTILITY CHARGES.    In connection with LESSEE's charges for heat and
electricity pursuant to Section 5 above, if the premises have a separate
electric meter, LESSEE  shall pay both charges that are separately metered at
the leased premises and a proportionate share of any charges that are not
separately metered, such as charges for operating the central boiler, chiller
and corridor lighting serving the building.

  B.  SOUTH ESSEX SEWERAGE DISTRICT.    LESSEE shall fully comply with all
regulations of the South Essex Sewerage District (SESD) now or hereafter in
effect, including prompt filing with LESSOR any documents required by SESD
regulations, and LESSEE agrees to indemnify and hold harmless LESSOR and OWNER
from any and all liability arising out of any noncompliance by LESSEE with such
regulations.

  C.  SNOW REMOVAL.   Notwithstanding any statement hereinabove to the contrary,
LESSOR and not LESSEE shall arrange and pay for snow removal services on all
common walkways serving the leased premises.

  D.  ELECTRIC SERVICE.  LESSEE agrees that in the event its average electricity
use at the leased premises is expected to exceed 200 kW per month during the
term of this lease, it will not self-generate, co-generate, or use a supplier of
electrical distribution service other than Massachusetts Electric Company at the
leased premises during the term of this lease or any extension(s) hereof.

  E.  ADDITIONAL RENT.    Notwithstanding the provisions of Section 4 above,
LESSEE's proportionate share of any increase in real estate taxes shall be based
on square footage leased by LESSEE as compared with the total leasable square
footage of the entire property of which the leased premises are a part, known as
Cummings Center ("the Property"), and not merely of the building.  Any such
increase shall otherwise be paid in full accordance with the terms of the
Section 4.

  F.  ACTIVITY AND USE RESTRICTION.    Except as provided below, the following
activities and uses are expressly prohibited at the Property:  residential uses
(except for facilities for adult congregate care/assisted living, senior
housing, nursing home uses and other adult residential facilities in certain
designated areas of the Property); child care, day care or public or private
elementary or secondary schools; a public park, playground or playing field, or
other activities involving more than casual contact with the ground; cultivation
of out-of-doors fruits and vegetables destined for human consumption; and
fishing or swimming in the ponds and other waterways on or adjacent to the
Property.  In addition, implementation of a health and safety plan is required
for construction, utilities maintenance and other intrusive activities which are
likely to involve extensive exposure to or contact with subsurface soils at the
Property.  A Notice of Activity and Use Limitation providing further information
has been recorded at the Essex South Registry of Deeds, as well as amendments
authorizing child care and a public elementary school in specific locations.

  G.  PROPERTY SURVEILLANCE.     LESSEE acknowledges that LESSOR may at any time
be conducting ongoing surveillance of the Property by means of surveillance
staff and remote television monitoring cameras in order to deter vandalism
and/or other damage to the Property.  Notwithstanding this surveillance, LESSEE
acknowledges and agrees that, as provided in Section 15 above, LESSOR is not
thereby or in any other way providing any security service for LESSEE or its
employees, agents, invitees, contractors and representatives.
<PAGE>
 
  H.  *LESSOR, at LESSOR's cost, shall construct standard office space according
to a mutually agreed upon plan attached hereto before or about the time LESSEE
takes possession of the leased premises.  Said space shall be air conditioned,
carpeted and completed with painted drywall partitions, acoustical tile
ceilings, recessed lighting, chrome pendent fire protection sprinklers, and 110V
convenience electrical wall outlets at regular intervals.

  I.  *LESSOR, if requested to do so by LESSEE  and at LESSEE's sole expense,
shall make alterations necessitated by LESSEE's use of the leased premises
according to a plan to be mutually agreed upon by both parties.  These
alterations shall be considered "nonbuilding standard" for maintenance purposes
pursuant to Section 9 of the lease.  At LESSEE's request, the charges for
certain alterations agreed to in advance and completed by LESSOR or LESSOR's
agents may be incorporated into the lease by separate amendment to be attached
hereto, amortized and then paid for by Lessee in the same manner as base rent
which shall otherwise be due.

  J.  *The parties acknowledge and agree that, as of the execution of this
lease, the leased premises have not been demised.  Accordingly, upon completion
of the modifications provided for herein, LESSOR shall measure the leased
premises, and if the size does not equal the total number of square feet set
forth in the initial paragraph of this lease, the parties shall execute an
amendment to this lease that adjusts the size and rent accordingly.

  K.  LESSOR represents and warrants to LESSEE that it is the exclusive managing
agent of the owner of the real property located at 60 Audubon Road, Wakefield,
Massachusetts and is the assignee of the landlord's interest under the lease
between The Equitable Life Assurance Society of the United States and LESSEE
dated October 29, 1993.  Such lease shall terminate as of June 30, 1998 and
LESSEE shall vacate said earlier facility on or prior to that date provide
LESSOR has completed LESSOR's work and made the leased premises ready for
occupancy by June 15, 1998.  Any extended occupancy of said earlier facility
beyond the commencement date of this lease shall be governed by Sections 10.9
and 10.13 of the prior lease.  Time is of the essence.



                                                              ____________LESSOR

                                                            ___/S/ M.H.___LESSEE
<PAGE>
 
                                 RIDER TO LEASE
                                  (CONTINUED)


  L.  At any one time during the initial term of this lease, LESSEE may request
larger similar space of approximately 30,000 square feet.  LESSEE shall give
LESSOR written notice of such requirement for larger space, and shall then
execute LESSOR's then current standard form lease, with modifications
substantially similar to those herein, for such larger space in the same or
other buildings of LESSOR at LESSOR's then current published rates within three
business of LESSOR's written notice to LESSEE that said larger space will be
available.  If LESSOR does not offer such larger similar space within six months
after receipt of written notice from LESSEE, then LESSEE shall have the option
within 30 days thereafter to terminate the unexpired portion of this lease,
without penalty and without any further obligation, either party to the other,
by serving LESSOR with 30 days written notice to that effect.  Cancellation of
the lease shall be LESSEE's exclusive remedy for any failure by LESSOR to offer
such larger similar space or any breach by LESSOR of the provisions of this
paragraph.  Time is of the essence.

  M.  *LESSEE'S agreement to subordinate this lease to any and all mortgages
and/or other instruments in the nature of a mortgage, now or at any time in the
future, is conditional upon the mortgagee's agreement that LESSEE's possession
will not be disturbed so long as LESSEE is not in default in the payment of rent
or other covenants or obligations hereof.

  N.  *LESSOR hereby represents that, to the best of its knowledge and belief,
the use of the leased premises for the purposes set forth in Section 3 is
permitted under the Massachusetts General Laws and the City of Beverly Zoning
Ordinance.  In the event, however, that the City of Beverly issues a citation to
LESSEE prohibiting the use of the leased premises for said purposes and said
citation is adjudged valid after LESSEE has exhausted all applicable appeals,
then LESSEE may cancel this lease by serving LESSOR with 30 days prior written
notice to that effect, and neither party shall have any further obligation to
the other.  Cancellation of the lease shall be LESSEE's exclusive remedy for any
breach by LESSOR of this representation or otherwise in connection with such
municipal action.

  O.  *The parties acknowledge and agree that, as of the execution of this
lease, the leased premises have not been demised.  Accordingly, upon completion
of the modifications provided for herein, LESSOR shall measure the leased
premises, and if the size does not equal the total number of square feet set
forth in the initial paragraph of this lease, the parties shall execute an
amendment to this lease that adjusts the size and rent accordingly.

  P.  If LESSOR exercises its right to relocate LESSEE pursuant to Section 22,
LESSOR or LESSOR's designated moving company shall, at LESSOR's expense, more
LESSEE's furniture, furnishings and equipment (including the reinstallation of
any computer or telecommunications wiring) from the leased premises to the new
similar facility designated by LESSOR.  LESSEE shall, at LESSEE's sole cost and
expense, properly disconnect, box , pack and otherwise prepare all items to be
moved.

  Q.  Notwithstanding the provisions of Section 27 to the contrary , prior to
the termination date of this lease, LESSEE may remove manufacturing equipment,
computer equipment, telephone equipment and furniture supplied and installed by
LESSEE if LESSEE has satisfactorily complied with all other conditions of this
lease and if LESSEE repairs any and all damage resulting from such removal and
restores the leased premises to their condition prior to the installation of
said equipment, all on a timely basis prior to the end of the lease term. Time
is of the essence.

  R.  *Whenever LESSOR's or LESSEE's consent, agreement or approval is required
under this lease, said consent, agreement or approval shall not be unreasonably
withheld or delayed.

  S.  *LESSOR agrees to erect signage designating two parking spaces in front of
the leased premises for short term visitor parking.  LESSOR shall have no
responsibility for enforcing said parking restriction.
<PAGE>
 
  T.  *Notwithstanding monthly rent as provided in Section 1 above, LESSEE may
discount each monthly rental payment due from July 1, 1998 through June 30, 1999
(only) according to the below schedule, provided that funds are wired to
LESSOR's bank account on or before the first business day of each month,
excluding Saturdays, Sundays, and holidays, and Lessee is not otherwise in
default of the lease or in arrears of any rent or invoice payments.  LESSEE
shall complete any documentation requested by LESSOR to implement these wire
transfers.  Time is of the essence.  Said documents shall be as follows:

       July 1, 1998 to July 30, 1998 discount of $19,086.83
       August 1, 1998 to June 30, 1999 discount of $1,612.41 per month



LESSOR: CUMMINGS PROPERTIES MANAGEMENT, INC.  LESSEE: WAKEFIELD ENGINEERING,INC.


   By:                                        By: /s/ Michael Hoffmann
      ----------------------------               ---------------------------  
                         President


   Date:
         -------------------------
<PAGE>
 
WAKEFIELD
ENGINEERING



APRIL 30, 1998

Cummings Properties
200 West Cummings Park
Woburn, MA 01801
Stephen Frohn



Steve,

Per our inspection of 60 Audubon Road on April 30th, please add the following
addendum to the Rider to Lease in paragraph K:

Lessee shall have complied with said Section 10.9 of the current lease dated
October 29, 1993 by removing and/or restoring the following:

        .  Damaged cement walls and floor
        .  Clean up of oil stains
        .  Waste treatment line
        .  Damaged wood walls


Cummings Property Management Inc.        Wakefield Engineering, Inc.

By:   /s/ Stephen M. Frohn V.P.          By:    /s/ Michael Hoffmann
    ---------------------------                 ------------------------
<PAGE>
 
WAKEFIELD
ENGINEERING



April 30, 1998

Cummings Properties
200 West Cummings Park
Woburn, MA 01801
Stephen Frohn


Steve,

Per our earlier conversation, we have agreed that the following items will be
included in our annual rent of $229,042.00:

        .  48" tail board loading facilities 
        .  Side lite office windows
        .  1 additional skylight
        .  Incandescent lighting within the prototype area only
        .  Sound board between prototype/engineering area and office space


Also, the final layout will be supplied to Cummings Properties no later than
Tuesday, May 5th.


Cummings Property Management Inc.        Wakefield Engineering, Inc.

By: /s/ Stephen M. Frohn V.P.            By: /s/ Michael Hoffmann
    ------------------------------           -----------------------