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                               NET LEASE AGREEMENT


      THIS NET LEASE AGREEMENT made and entered into this 9th day of February,
1999, by and between Jaguar II, LC, a Virginia LLC, having an address as 1512
Windstone Drive, Vienna, Virginia 22182-15387, hereinafter referred to as
"Lessor", and SENSYS TECHNOLOGIES INC., a Delaware corporation, having an
address as 8419 Terminal Road, Newington, Virginia 22122-1430, hereinafter
referred to as "Lessee".


                               W I T N E S S E T H:


      1. PREMISES: Lessor hereby leases to Lessee, and Lessee hereby leases from
Lessor, two (2) parcels of land (the "Land"), more particularly described in
Exhibit A attached hereto and made a part hereof, consisting of approximately
4.0368 acres and the three (3) buildings located thereon (the "Buildings")
containing an "agreed upon" sixty-seven thousand two hundred twenty (67,220)
gross square feet of space in the aggregate. The Land and Buildings are
hereinafter collectively referred to as the "demised premises". Lessee's
interest in this Lease is subject to all covenants and restrictions of record
and all applicable zoning, municipal, county, state and federal laws, statutes,
codes, ordinances, rules and regulations affecting the demised premises.

      2. TERM: The lease term of fifteen (15) years shall commence on the date
of the acquisition of the demised property by Jaguar II of this Lease by the
last of the parties executing the same. If Lessor is unable to acquire said
property by June 30, 1999, unless such inability to acquire is the result of
action or inaction of Lessee, this Lease, at option of Lessee, shall terminate.
Inasmuch as Lessee and Newington Concrete, its sublessee, are currently, and
have been for approximately the last ten (10) years, the sole occupants of the
entire demised premises, Lessor is hereby relieved of any obligation to tender
delivery of possession of the demised premises to Lessee, and Lessee agrees that
it has, as of the commencement date of this Lease, accepted possession of the
demised premises in their then "as is" condition without any obligation or
liability of Lessor to do any work in, on or to any portion of the demised
premises to make the same usable by Lessee or any sublessee of Lessee for the
permitted purposes, it being understood and agreed that this is a net lease, and
Lessor shall receive base rent free and clear of any charge or expense and that
Lessee is obligated, and shall be responsible, for the repair, maintenance and
replacement of every portion of the demised premises and the obtaining and
procurement of all requisite insurance and utility and all other services. If
this Lease commences on other than the first day of a calendar month or expires
on other than the last day of a calendar month, the installment of base rent for
the applicable month will be prorated and paid on a per diem basis based on the
actual number of days in the applicable calendar month. The lease term shall
expire on the day preceding the fifteenth (15th) anniversary of the commencement
date plus, if the commencement date is other than the first day of a calendar
month, the number of days between the commencement date and the last day of the
month in which the commencement date occurred.

      3.     RENT:

      a.    As base rent for the demised premises, Lessee shall pay to Lessor
            Four Hundred Twenty Thousand One Hundred Twenty-five and no/l00
            ($420,125.00) Dollars per annum for the first lease year. Commencing
            on the first day of the second lease year and continuing on the
            first day of each lease year thereafter throughout the initial term
            of this Lease, the base rent shall, as of the first day of each such
            lease year, be increased to one hundred three (103%) percent of the
            base rent payable for the preceding lease year. If the commencement
            date occurs on a day other than the first day of the month, base
            rent for the first month of the term shall be apportioned. Such
            first month's base rent shall, unless provided otherwise herein or
            by written agreement between Lessor and Lessee, be due and payable
            on the commencement date.

      b.    Base rent stipulated for each of the applicable lease years shall be
            paid in equal one-twelfth (1/12th) installments in advance on the
            first day of each calendar month for the applicable lease year. Base
            rent and all other items of rent or payments due Lessor under this
            Lease shall be paid to Lessor at the address of Lessor set forth
            above or at such other address and/or such other party as Lessor
            may, from time to time, designate by written notice to Lessee in the
            manner hereafter set forth.

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      c.    Lessee covenants and agrees to pay all licenses, taxes, sales taxes
            and assessments of every kind and character imposed by any
            governmental body, on, against or in connection with the operation
            of the business conducted on the demised premises, or against
            Lessee's property in or on the demised premises or on any
            installment of base rent or item of additional rent or other charge
            payable by Lessee under this Lease.

      4. REPAIR AND MAINTENANCE: Lessee shall, in accordance with Legal
Requirements, as such term is hereinafter defined, repair and maintain in good
condition the entire demised premises and, where necessary, make such
replacements to the Buildings and all improvements, including, without
limitation, the roof, structural and non-structural portions of the Buildings,
all landscaping, curbing, sidewalks, roads (including, without limitation, any
private road or area encumbered by ingress and egress easements), parking areas,
driveways and all the Buildings systems and generally keep the demised premises
clean. If Lessor or Lessee is required by any municipal or governmental
directive to sort and separate trash and refuse, Lessee shall sort and separate
its trash and refuse as it or Lessor shall be directed by the applicable
municipal or governmental authority, as the case may be. Lessee agrees to keep
and maintain the property to at least the same standard of care as it is
presently being maintained, and in that regard, the parties agree that if, by
good operational practice, an item could be repaired rather than replaced,
Lessee may, at its option, repair the item rather than replace the same;
however, it being understood and agreed that nothing contained in this sentence
shall relieve or release Lessee from replacing any item that, by good
operational practice, should be replaced rather than repaired. Further, Lessee
hereby expressly covenants and agrees that Lessee shall, at its sole cost and
expense, throughout the term of this Lease, obtain and maintain a standard
service contract on the HVAC systems and equipment. Further, at the expiration
or earlier termination of this Lease, Lessee shall be required to remove from
the property the trailers now located on the Land which are owned by Lessee and
are not the property of Lessor and all the items listed on Schedule I attached
hereto and made a part hereof, and Lessee shall be obligated to restore any area
of the Land and/or Buildings damaged by the installation and/or removal of the
trailers and the items listed on Schedule I.

      5. COMPLIANCE WITH REQUIREMENTS OF LAW: Lessee, at its sole cost and
expense, shall promptly comply with all laws, statutes, codes, ordinances,
rules, orders, regulations and requirements (collectively, the Legal
Requirements) of the Federal, State, County and local government and of any and
all their departments and bureaus with jurisdiction over the demised premises,
and with any directives of any public officer or officers which shall impose any
violation, order or duty upon the demised premises and/or relate to the
correction, prevention and/or abatement of nuisances or other grievances in,
upon or connected with the demised premises during the term hereof. Lessee
shall, at Lessee's own cost and expense, also promptly comply with and obey all
rules, orders and regulations of all insurance carriers and any fire
underwriting or rating authority relating to the demised premises. Any
governmental or municipal permits, approvals or consents required in order for
Lessee to be able to use the demised premises for the purposes for which Lessee
intends, and is permitted hereunder, to use the demised premises, if necessary,
shall be obtained by Lessee, at Lessee's sole cost and expense, and any failure
of Lessee to obtain such permits, approvals or consents shall not relieve Lessee
of its obligations hereunder.

      6. SERVICES: Inasmuch as this is a triple net lease, Lessor shall not be
obligated to provide or furnish any service of any kind to Lessee.

      7. ALTERATIONS: Lessee shall make no additions, installations, alterations
or changes in or to the demised premises without obtaining the prior written
permission of Lessor, which consent Lessor may withhold in its sole and absolute
discretion except Lessor shall not unreasonably withhold, delay or condition its
approval to any proposed interior work so long as the proposed work (i) would
not adversely affect any of the Buildings' exteriors, roofs, windows or doors or
frames therefor, structural integrity or systems, (ii) would not increase the
costs of operating or managing the Property, (iii) would not increase the scope
or costs of Lessor's obligations under this Lease and (iv) does not consist of,
or require, any demolition of, or additions to, load bearing walls or exterior
walls. The work or type of work described in clauses (i) through (iv) of this
paragraph 7 is hereinafter described as "Structural Work", and interior
non-structural work for which Lessor's approval shall not be unreasonably
withheld, delayed or conditioned is hereinafter referred to as "Non-Structural
Work". If Lessor's approval or denial of approval to any Non-Structural Work is
not received within five (5) business days of Lessor's receipt of all the items
required for it to be able to make a determination whether to approve or not
approve the proposed work, such failure to respond shall be deemed an approval
to such Non-Structural Work. Lessor and Lessee shall, at Lessor's option, every
six (6) months throughout the term of this lease, inspect the additions and
alterations made by Lessee since the prior inspection. In any event, all
installations, alterations or work done by Lessee shall at all times comply
with:

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      a.   Laws, rules, orders and regulations of all governmental or municipal
           bodies, authorities, departments or agencies having jurisdiction
           thereof and such rules and regulations as Lessor shall promulgate.

      b.   Plans and specifications prepared by and at the expense of Lessee
           theretofore submitted to Lessor for its prior written approval. No
           installations, alterations or any other work shall be undertaken,
           started or begun by Lessee, its agents, servants or employees, until
           Lessor has approved such plans and specifications.

      c.   Lessee agrees to pay Lessor's reasonable costs and expenses of
           reviewing any plans and specifications submitted for Lessor's review.

      8. ACCESS: Lessee shall permit Lessor and others authorized by Lessor to
enter upon the demised premises at all reasonable times (and at all times where
an emergency exists or where Lessor, in the exercise of its reasonable
discretion, determines access at other times is necessary to protect damage to
property or prevent injury to people) (i) to examine the condition thereof and
conditions of Lessee's occupancy, (ii) to exhibit the same to prospective
tenants, prospective purchasers, mortgagees and/or prospective mortgagees or
(iii) to make such repairs, additions or alterations therein as Lessor may deem
necessary or to comply with its obligations hereunder or which Lessor shall, at
its option (but without any obligation to do so), elect to make, including,
without limitation, painting the exterior of the Buildings. Lessor agrees that
it shall have no right to enter any area that, pursuant to Federal government
regulations or directives or by customer contracts or agreements, is restricted
so as to prohibit entry by Lessor. In connection with the foregoing, Lessor
shall be allowed to take all materials into and upon the demised premises that
may be required for such repairs, improvements or alterations, without the same
constituting an eviction of Lessee, in whole or in part, and without any
abatement or diminution of the basic rent or additional rent. In making of such
repairs or alterations, Lessor, to the extent practicable and consistent with
efficiency and economy, will exercise reasonable diligence so as to minimize the
disturbance of or interference with the business of Lessee. Nothing herein
contained, however, shall be deemed or construed to impose on Lessor any
obligation, responsibility or liability whatsoever for the care, supervision or
repair of the demised premises or any part thereof, other than as herein
provided.

      9. Intentionally deleted.

      10. USE: Lessee shall not use, or permit the use of, the demised premises
contrary to any applicable statute, ordinance, law, rule or regulation or in
violation of the certificate of occupancy.

      11. LIABILITY: Lessee shall save and hold Lessor harmless from all
liabilities, charges, expenses (including reasonable counsel fees) and costs on
account of all claims for damages and otherwise and/or suits for or by reason of
any injury or injuries to any person or property of any kind whatsoever, whether
the person or property of Lessee, its agents or employees or third persons, from
any cause or causes whatsoever while on or upon or in proximity to said premises
or due to any breach of a covenant herein by Lessee or to Lessee's use and
occupancy of the demised premises. Nothing contained herein or elsewhere in this
Lease shall require Lessee to hold Lessor harmless or indemnify Lessee from
Lessor's negligent acts or omissions.

      12. SURRENDER AND TERMINATION: All fixtures, equipment, improvements and
appurtenances attached to or built into the demised premises prior to or during
the term, whether by Lessor, at its expense or at the expense of Lessee, or by
Lessee, shall be and remain part of the demised premises (other than for those
items listed on Schedule I) and shall not be removed by Lessee at the end of the
term, unless Lessor, at least one hundred twenty (120) days prior to the
expiration of the term, notifies Lessee to remove the same, it being understood
and agreed that Lessee, at its sole cost and expense but without any demand of,
or notice by, Lessor to do so, must, at or prior to the expiration or earlier
termination of this Lease, remove the items listed on Schedule I and repair all
damages to the Buildings or Land occasioned by, resulting from, or arising out
of, the original installation and/or removal of said items. All of Lessee's
removable trade fixtures and removable business equipment (no Buildings system
or equipment shall be, or be deemed to be, Lessee's business equipment) may be
removed by Lessee upon condition that such removal does not materially damage
the Buildings and that the repair of any such damage shall be made by Lessee
prior to the expiration of the term of this Lease, or if Lessee fails to make
such repairs, the cost of repairing any damage to the Buildings arising from
such removal shall be done by Lessor, but be paid by Lessee. Any property of
Lessee or of any subtenant or occupant that Lessee has the right to remove or
may hereunder be required to remove which shall remain in the Buildings after
the expiration or termination of the term of this Lease shall be deemed to have
been abandoned by Lessee, and either may be retained by Lessor


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as its property or may be disposed of in such manner as Lessor may see fit;
provided, however, that, notwithstanding the foregoing, in the event of any
failure of Lessee to promptly remove the items requested by Lessor to be removed
or for which Lessee is required to remove and/or restore any damage to the
demised premises occasioned by such removal, Lessor, at Lessee's cost and
expense, may remove the items Lessee failed to remove and/or effect all repairs
to the demised premises. If such property or any part thereof shall be sold,
Lessor may receive and retain the proceeds of such sale and apply the same, at
its option, against the expenses of the sale, the cost of moving and storage,
any arrears of base rent, additional rent or other charge payable hereunder and
any damages to which Lessor may be entitled hereunder or pursuant to law. Upon
the expiration or other termination of the term of this Lease, Lessee shall quit
and surrender to Lessor the demised premises, broom clean, in the same order and
condition, as of the date hereof, ordinary wear excepted, and Lessee shall (i)
remove all of its property and other items that it is permitted or required
hereunder to remove and (ii) repair all damage to the demised premises
occasioned by such removal. Lessee's obligation to observe or perform this
covenant shall survive the expiration or other termination of the term of this
Lease.

      13. INDEMNITY: Lessor, its agents and its and their employees shall not be
liable for any damage to property of Lessee or of any other party claiming by,
through or under Lessee, nor for the loss or damage to any property of Lessee by
theft or otherwise. Lessee shall, at its own cost and expense, be responsible
for the repairs or restoration due to, or resulting from, any theft or
otherwise. Lessor or its agent shall not be liable for any injury or damage to
persons or property resulting from fire, explosion, falling plaster, steam, gas,
electricity, electrical disturbance, water, rain or snow or leaks from any part
of the Buildings or from the pipes, appliances or plumbing works or from the
roof, street or sub-surface or from any other place or by dampness or by any
other cause of whatsoever nature; nor shall Lessor or its agents be liable for
any such damage caused by persons in the Buildings or caused by operations in
construction of any private, public or quasi-public work; nor shall Lessor be
liable for any defect (latent or otherwise) on, in or upon the demised premises.
Lessee shall reimburse and compensate Lessor as additional rent for all
expenditures made by or damages or fines sustained or incurred by, Lessor due to
non-performance or non-compliance with or breach or failure to observe any term,
covenants or condition of this Lease upon Lessee's part to be kept, observed,
performed or complied with.

      14. NO WAIVER: The failure of Lessor to seek redress for violation of,
or to insist upon the strict performance of, any covenant or condition of this
Lease shall not prevent a subsequent act, which would have originally
constituted a violation from having all the force and effect of an original
violation. The receipt by Lessor of rent with knowledge of the breach of any
covenant of this Lease shall not be deemed a waiver of such breach. No
provision of this Lease shall be deemed to have been waived by Lessor unless
such waiver be in writing signed by Lessor. No surrender of this Lease shall be
effective without Lessor's written agreement to accept such surrender. No
payment by Lessee, or receipt by Lessor, of a lesser amount than the full rent,
additional rent or payment obligation hereunder shall be deemed to be other
than on account for the sum or sums stipulated hereunder, nor shall any
endorsement or statement on any check or any letter accompanying a payment by
Lessee be deemed an accord and satisfaction and Lessor may accept such check or
payment without prejudice to Lessor's right to recover the balance of such
rent, additional rent or other payment or pursue any other remedy available to
Lessor. No waiver, on the part of Lessor, its successors or assigns, of any
default or breach by of any covenant, agreement or condition of this Lease
shall be construed to be a waiver of the rights of Lessor as to any prior or
future default or breach by Lessee.

      15. SUBORDINATION: This Lease is subject and subordinate to the lien of
any and all mortgages, deeds of trust or other security devices which may now or
hereafter affect or encumber all or any portion of the demised premises. This
clause shall be self-operative and no further instrument of subordination shall
be required by any mortgagee, or holder of another security device or holder of
a ground leasehold interest. In confirmation of such subordination, however,
Lessee agrees to execute and acknowledge any documents required to effectuate
such subordination or, at the option of any of such holder of mortgage or deed
to secure debt, to make this Lease or any option granted herein prior to the
lien of such mortgage, deed of trust or other security devices, as the case may
be, provided, in the case of a subordination, the holder of the mortgage or deed
of trust agrees, so long as Lessee is not in default under this Lease, (i) not
to disturb Lessee's possession or rights under this Lease and (ii) to recognize
Lessee as a direct tenant subsequent to such holder's acquisition of title, but,
in no event, shall the acquirer of Lessor's interest be obligated for, or liable
to Lessee as a result of, any failure in Lessor's


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performance under this Lease prior to such party's acquisition of title nor
shall such party (a) be bound by any payment of base rent or item of additional
rent paid more than one (1) month in advance, (b) be liable for any damages or
subject to any offset or defense by Lessee for any act or omission of Lessor
prior to such party's acquisition of title or (c) be bound by any termination,
amendment, modification, cancellation or surrender of this Lease made without
such holder's consent.

      Notwithstanding the foregoing, in the event any such mortgagee or the
holder of any deed to secure debt, other security device or ground leasehold
interest shall elect to make the lien of this Lease prior to the lien of its
mortgage, deed to secure debt, other security device or ground leasehold
interest, then, upon such party giving Lessee written notice to such effect,
this Lease shall be deemed to be prior in lien to the lien of such mortgage deed
to secure debt, other security device or ground leasehold interest, whether
dated prior or subsequent thereto.

      16.   INSURANCE:  A. Lessee shall maintain at its own cost and expense:

            a. COMPREHENSIVE GENERAL LIABILITY INSURANCE covering the demised
premises on an occurrence basis with minimum limits of liability in an amount
equal to Five Million and 00/100 ($5,000,000.00) Dollars for bodily injury,
personal injury or death to one or more persons, and a single limit of Two
Million and 00/100 ($2,000,000.00) Dollars with respect to damage to property by
water or otherwise. Such policy shall name Lessor as an additional insured and
shall provide that the same may not be cancelled or terminated without at least
thirty (30) days' written notice to Lessor by the insurance company issuing such
policy, and that no act or failure to act on the part of Lessee shall invalidate
such insurance as to Lessor; and

            b. WORKER'S COMPENSATION AND EMPLOYER'S LIABILITY INSURANCE in
accordance with the laws of the Commonwealth of Virginia; and

            c. FIRE INSURANCE in an amount adequate to cover the cost of full
replacement of the Buildings and all equipment and all decorative items
(including but not limited to, carpeting, wall coverings, lighting fixtures and
non-realty fixtures and contents) in the Buildings and all other improvements in
the event of fire, perils covered by extended coverage, vandalism, malicious
mischief and sprinkler leakage with only such deductible as shall be approved in
writing by Lessor and which policy shall name Lessor as the sole loss payee
together with business interruption insurance in an amount at least equal to one
(1) year's aggregate real estate taxes and impositions, rent, additional rent
and other charges payable under this Lease to Lessor, which insurance shall be
payable solely to Lessor, and to the extent Lessor receives the proceeds of the
business interruption insurance, Lessor shall (but only to the extent that it
receives the same) credit the same to the rent, additional rent and other
charges payable to Lessor hereunder as such items become due and payable, and
the balance thereof shall be held by Lessor in trust on the basis provided in
paragraph 19 of this Lease.

            d. OTHER INSURANCE in such amounts as shall then be readily
available and commonly insured against for properties similar to the demised
premises or that Lessor's mortgagees may require.

            In the event Lessee fails to carry the aforesaid insurance coverage,
Lessor, at its option, shall have the right to carry any or all of the insurance
hereinabove provided for (and Lessor shall have the insurance carrier issue a
waiver of subrogation clause in favor of Lessee) and in such event, Lessee
agrees to reimburse Lessor for the entire cost of the same; or, if Lessor's
policies shall cover more than the demised premises, Lessee shall pay its
proportionate share of the premium for such insurance, which proportionate share
shall be determined by the insurance carrier (or agent of the carrier) issuing
the said policy, the same to be paid by Lessee to Lessor within fifteen (15)
days after Lessor renders a bill therefor.

            B. Any insurance procured by Lessee shall be issued by a company
approved by Lessor, licensed to do business in the Commonwealth of Virginia and
having a policy rating of at least A and financial rating of at least Class X in
the most current edition of Best's Insurance Reports shall contain endorsements
that (a) such insurance may not be cancelled or amended with respect to Lessor
without thirty (30) days' written notice by registered mail to Lessor by the
insurance company; (b) Lessee shall be solely responsible for payment of
premiums and Lessor shall not be required to pay any premiums for such
insurance; (c) in the event of payment of any loss covered by the policy
referred to in 16A.c, Lessor shall be paid first by the insurance company for
its loss as its interest may appear; and (d) no act of Lessee will invalidate
any such insurance as to the interest of Lessor thereunder.

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            If requested in writing by Lessor, Lessee shall include as a named
insured, additional named insured or loss payee under said policies, such other
party or parties as Lessor may designate.

            A duplicate policy of all such insurance shall be delivered by
Lessee to Lessor within ten (10) days of issuance of such policy by the
insurance company together with proof of payment satisfactory to Lessor
evidencing payment of the premium in full or setting forth a payment plan for
each applicable policy; and the duplicate policy of all renewals at least thirty
(30) days prior to the expiration of such existing policies together with proof
of payment satisfactory to Lessor evidencing payment of the premium in full for
each applicable policy. The minimum limits of any insurance coverage required
herein shall not limit Lessee's liability under paragraph 13.

            C. If Lessor's mortgage shall require that an escrow be established
to assure payment of the requisite insurance coverages, Lessee shall, in
addition to paying the installment of the then current premiums at the execution
of this Lease, escrow with Lessor, generally on the basis provided in paragraph
27, the amounts necessary to initially establish that escrow and make the
monthly payments thereafter required so that Lessor will, at all times, have
available an amount sufficient to pay at least thirty (30) days before each
premium shall become due, the premium so becoming due.


      17. DEFAULT: Time is of the essence with regard to the performance of
Lessee's obligations under this Lease. Any of the following constitutes a
default of this Lease by Lessee:

            a.    Failure to pay any installment of base rent, item of
                  additional rent or other charge payable under this Lease
                  within ten (10) days of Lessor's written demand for payment.

                  Lessee shall pay Lessor interest at the per annum rate of two
                  (2%) percent in excess of the prime rate, as such term is
                  hereinafter defined, charged by Citibank, N.A. (or if such
                  rate be illegal, at the maximum rate permitted by law, and any
                  payment in excess of that which is permitted by law shall, and
                  be deemed to be, an advance payment of base rent and shall be
                  applied against the installments of base rent next becoming
                  due) on all payments due under this Lease that are not made
                  within ten (10) days of their due date calculated from the
                  date when due until paid in full.

            b.    Failure to cure any non-monetary default of Lessee's
                  obligations under this Lease for a period of thirty (30) days
                  after written notice specifying the nature of the default,
                  except that in the event such default is not of a type
                  specified in subparagraphs 17c or 17d and cannot be cured
                  within said thirty (30) day period, but is susceptible to cure
                  within a reasonable period of time, such cure period shall be
                  extended for such reasonable period of time, provided Lessee
                  promptly commences to cure the default within said thirty (30)
                  day period and thereafter diligently cures such default.

            c.    Lessee files a voluntary petition in bankruptcy or is
                  adjudicated insolvent or a bankrupt, or makes an assignment
                  for the benefit of creditors, or files a petition for relief
                  under any applicable bankruptcy law, or consents to the
                  appointment of a trustee or receiver of all or any substantial
                  part of its property; or

            d.    An involuntary petition under any applicable bankruptcy law is
                  filed against Lessee and is not vacated within ninety (90)
                  days.

      18. LESSOR'S REMEDIES: Upon Lessee's default and the expiration of any
applicable grace period, Lessor may (at Lessor's option and in addition to all
other rights provided in this Lease, at law or in equity) take any one or more
of the following actions without further notice or demand.

            a.    Terminate this Lease and Lessee's right of possession of the
                  demised premises, and recover all damages to which Lessor is
                  entitled under law, specifically including, but without
                  limitation, all of Lessor's expenses of reletting (including,
                  without limitation, rental concessions to new tenants,
                  repairs, alterations, legal fees and brokerage commissions for
                  the period on or prior to the expiration date of this Lease
                  set forth in paragraph 2 of this Lease). If Lessor elects to
                  terminate this Lease, every obligation of the


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                  parties shall cease as of the date of such termination, except
                  that Lessee shall remain liable for payment of rent and
                  performance of all other terms and conditions of this Lease to
                  the date of termination.

            b.    Terminate Lessee's right of possession of the demised premises
                  without terminating this Lease, in which event Lessor may, but
                  shall not be obligated to, relet the demised premises, or any
                  part thereof, for the account of Lessee, for such rent and
                  term and upon such other conditions as are acceptable to
                  Lessor. For purposes of such reletting, Lessor is authorized
                  to redecorate, repair, alter and improve the demised premises
                  to the extent necessary in Lessor's sole discretion. Until
                  Lessor relets the demised premises, Lessee shall remain
                  obligated to pay rent to Lessor as provided in this Lease. If
                  and when the demised premises are relet and if a sufficient
                  sum is not realized from such reletting after payment of all
                  Lessor's expenses of reletting (including, without limitation,
                  rental concessions to new tenants, repairs, alterations, legal
                  fees and brokerage commissions) to satisfy the payment of rent
                  due under this Lease for any month, Lessee shall pay Lessor
                  any such deficiency upon demand. Lessee agrees that Lessor may
                  file suit to recover any sums due Lessor under this paragraph
                  18b from time to time and that such suit or recovery of any
                  amount due Lessor shall not be any defense to any subsequent
                  action brought for any amount not previously reduced to
                  judgment in favor of Lessor.

            c.    Terminate this Lease and Lessee's right of possession of the
                  demised premises, and recover from Lessee the net present
                  value of the rent due from the date of termination until the
                  stated expiration date, discounted at the lesser of the prime
                  rate of Citibank, N.A. as of the date of termination or five
                  (5%) percent per annum.

            d.    Re-enter and repossess the demised premises and remove all
                  persons and effects therefrom, by summary proceeding,
                  ejectment or other legal action. Lessor shall have no
                  liability by reason of any such re-entry, repossession or
                  removal.

            d.    Pursue any other remedy now or hereafter available to Lessor
                  under the laws or judicial decisions of the state wherein the
                  demised premises are located. Unpaid installments of rent and
                  other unpaid monetary obligations of Lessee under the terms of
                  this Lease shall bear interest from the date due at the lesser
                  of thirteen (13%) percent per annum or the maximum rate then
                  allowable by law.

            e.    If Lessor takes possession pursuant to this paragraph 18, with
                  or without terminating this Lease, Lessor may, at its option,
                  enter unto the demised premises, remove Lessee's improvements,
                  signs, personal property, equipment and other evidences of
                  tenancy, and store or dispose of them, at Lessee's risk and
                  expense or as Lessor may see fit, and take and hold possession
                  of the demised premises, provided, however, that if Lessor
                  elects to take possession only without terminating this Lease,
                  such entry and possession shall not terminate this Lease or
                  release Lessee, in whole or in part, from the obligation to
                  pay the base rent and additional rent and other charges
                  payable under this Lease for the full term or from any other
                  obligation under this Lease.

            f.    Notwithstanding anything to the contrary hereinbefore
                  contained in this paragraph 17, Lessor shall not be entitled
                  to double rent. In other words, monies collected by Lessor in
                  reletting shall (net of reletting expenses) be applied against
                  Lessor's damages.

            This Lease shall not be deemed to be terminated by Lessor's entry on
the demised premises or by any other act unless Lessor specifically expresses
its intent to terminate this Lease.

            Lessor's remedies in this paragraph 18 are cumulative and in
addition to any other remedies available at law or in equity.

      19. DESTRUCTION - FIRE OR OTHER CAUSE: If the demised premises shall be
damaged by any casualty, Lessee shall promptly and diligently repair (which term
shall include, without limitation, re-equip and re-fixture) the demised premises
to the condition or state


                                     - 7 -
<PAGE>   8

in which the demised premises were immediately prior to the casualty, it being
understood that there shall be no abatement of any rental payable hereunder (but
Lessor shall, to the extent of the net amount of business interruption insurance
proceeds actually received by Lessor for the applicable period, credit the same
against the rental payable under this Lease for said applicable period). All
proceeds payable under the fire and extended casualty insurance Lessee is
obligated to procure and obtain pursuant to paragraph 16c of this Lease shall be
paid to Lessor and shall (other than for the portion thereof representing
business interruption proceeds) be held in trust and Lessor shall make the
insurance proceeds being held in trust available to Lessee as the work
progresses generally on the same basis and subject to the same provisions as an
institutional construction lender would advance the proceeds of its construction
loan.

      20. LEGAL FEES: In the event it shall become necessary for either party at
any time to institute any legal action or proceedings of any nature for the
enforcement of this Lease, or any of the provisions hereof, or to employ an
attorney-at-law therefor and said party prevails in such action or proceedings,
then the non-prevailing party shall pay to the prevailing party such prevailing
party's costs (including all reasonable attorneys' fees) incurred in such action
or proceedings.

      21. CONDEMNATION: If all of the Buildings are taken by or under the power
of eminent domain (or conveyance in lieu thereof), this Lease shall terminate on
the date the condemning authority takes possession. In all other cases of any
taking of the Buildings or the Land by the power of eminent domain (or
conveyance in lieu thereof), Lessor shall have the option of electing to
terminate this Lease except that, if more than thirty (30%) percent of the
usable area of the Improvements be so taken, Lessee shall have the right to
terminate this Lease provided Lessee is not in default under this Lease and
written notice of such election is received by Lessor within thirty (30) days of
the taking. If neither Lessor nor Lessee elects to terminate, Lessor shall do
the work necessary so as to constitute the portion of the Buildings not so taken
a complete architectural unit and Lessee shall do all other work necessary for
it to use and occupy the demised premises for its permitted purpose. Rent shall
be equitably adjusted, as of the date the condemning authority permanently
acquires possession of the application portion of the demised premises. Lessee
shall not be entitled to, hereby expressly waives, and hereby assigns to Lessor
all Lessee's right, title and interest in and to, any condemnation award for any
taking (or consideration paid for a conveyance in lieu thereof), whether whole,
partial, temporary or permanent, and whether for diminution of the value of
Lessee's interest in this Lease or term thereof or to the lease improvements or
for any other claim or damage, including, without limitation, severance damages
and loss of, or damage to, Lessee's trade fixtures, except Lessee shall not be
precluded from seeking a separate claim for business damages or moving expenses
against the condemning authority provided any awards or proceeds sought by, or
paid to, Lessee does not reduce or diminish in any way or amount the awards or
proceeds otherwise payable to Lessor.

      22. ASSIGNMENT AND SUBLETTING: Lessee shall not assign this Lease or
sublease all or any portion of the demised premises during the term of this
Lease (or any extension thereof) without first obtaining the written consent of
Lessor, such consent to be not unreasonably withheld. Lessor hereby consents to
a sublease of approximately six thousand (6,000) gross square feet of space in
the building known as 8417 C Terminal Road to Newington Concrete.

      23. Intentionally deleted.

      24. Intentionally deleted.

      25. MECHANICS' LIENS: Neither Lessor nor the property shall be liable for
any labor, services or materials furnished or to be furnished to Lessee upon
credit, and no mechanic's or other lien for any such labor, services or
materials shall attach to, encumber or in any way affect the reversionary
interest or other estate or interest of Lessor in and to the Buildings or the
Land. Nothing in this Lease shall be construed as a consent by Lessor to subject
Lessor's reversionary interest in the demised premises to liability under any
lien or other law. If, as a result of any work or installation made by, or on
behalf of Lessee, or Lessee's maintenance, repair or replacement of the demised
premises, a claim of lien or lien is filed against the demised premises or all
or any portion of the Buildings or bond off the Land, within ten (10) days after
it is filed, Lessee shall either satisfy the claim of lien or lien. If Lessee
fails to do so within the ten (10) day period, Lessor may satisfy the lien, and
Lessee shall reimburse Lessor for all Lessor's costs and expenses (including
reasonable attorneys' fees) incurred in connection therewith.

      26. NOTICES: All notices by Lessee to Lessor or by Lessor to Lessee with
regard to this Lease must be in writing and shall be deemed conclusively
delivered when same are either hand delivered, or deposited in the U.S. mail,
postage prepaid, certified, return receipt requested,


                                     - 8 -
<PAGE>   9

or delivered by a nationally recognized courier for overnight delivery with such
delivery charge being prepaid, if to Lessor, addressed to Lessor at the address
set forth for Lessor on page 1 of this Lease or if to Lessee, at the address set
forth for Lessee on page 1 of this Lease prior to Lessee's initial occupancy of
the demised premises and thereafter with a duplicate to Lessee at the demised
premises. Either party hereto may, by notice given as aforesaid, designate a
different address or addresses for notices.

      27. REAL PROPERTY TAXES AND ASSESSMENTS: a. Lessee shall pay (and furnish
Lessor with proof of payment satisfactory to Lessor) prior to delinquency all
real property taxes and assessments. As used herein, the term "real property
taxes and assessments" shall include any form of real estate tax or assessment,
general, special, ordinary or extraordinary, and any license fee, commercial
rental tax, improvement bond or bonds, levy or tax (other than inheritance,
personal income or estate taxes) imposed on the Land and/or Buildings by any
authority having the direct or indirect power to tax, including any local, city,
state or federal government, or any school, agricultural, sanitary, fire,
street, drainage or other improvement district thereof, as against any legal or
equitable interest of Lessor in the Land and/or Buildings, as against Lessor's
right to rent or other income therefrom or as against Lessor's business of
leasing the Land and/or Buildings and all costs and fees (including attorneys'
fees) incurred by Lessor in contesting any tax or assessment and/or negotiating
with the public authorities as to the same. The term "real property taxes and
assessments" shall not include any income tax paid or payable by Lessor but
shall also include any tax, fee, levy, assessment or charge (i) in substitution
of, or in addition to, partially or totally, any tax, fee, levy, assessment or
charge hereinabove included within the definition of "real property taxes and
assessments", or (ii) the nature of which was hereinbefore included within the
definition of "real property taxes and assessments" or (iii) which is imposed by
reason of this transaction or any modification or changes hereto. If at any time
during the term of this Lease, under the laws of the State or any political
subdivision thereof in which the demised premises are situated, a tax or excise
on, or measured in whole or in part by, rents or gross receipts' or any other
tax, however characterized, is levied or assessed by said State or political
subdivision against Lessor or the basic rent expressly reserved hereunder in
addition to or as a substitute in whole or in part for taxes assessed or imposed
by said State or political subdivision on land and/or Buildings (such as, for
example, the present Commonwealth of Virginia sales tax on rents or a Fairfax
County gross receipts tax, the same shall be included within the term
"Impositions", and Lessee covenants to pay such tax or excise on, or measured
by, rents or gross receipts or other tax, but only to the extent of the amount
thereof which is lawfully assessed or imposed upon Lessor and which was so
assessed or imposed as a direct result of Lessor's ownership of the demised
premises, or of this Lease or of the rentals accruing under this Lease, it being
the intention of the parties hereto that the basic rent to be paid hereunder
shall be paid to Lessor absolutely net without deduction of any nature
whatsoever. The payments to be made by Lessee pursuant to this section shall be
made before any fine, penalty, interest or cost may be added thereto for the
nonpayment thereof. Notwithstanding anything hereinbefore contained to the
contrary, any assessments (that are not the result of, or not attributable to,
Lessee's acts or omissions) allocable to any period beyond the lease term shall
be paid by Lessor.

      b. Further, Lessee shall pay, prior to delinquency, all taxes assessed
against and levied upon trade fixtures, furnishings, equipment and all other
personal property of Lessee contained in the demised premises. When possible,
Lessee shall cause said trade fixtures, furnishings, equipment and all other
personal property to be assessed and billed separately from the real property of
Lessor.

      c. Any tax year commencing during any lease year shall be deemed to
correspond to such lease year. If Lessor's mortgagee shall require a tax escrow,
then Lessee shall, in addition to paying the then current tax installment at the
execution of this Lease, pay to Lessor on account of the semi-annual installment
of each such real property tax and assessment next to become due, an amount
equal to the aggregate of such semi-annual installments multiplied by a
fraction, the numerator of which shall be the remainder resulting from the
subtraction of the number of months intervening between the Commencement Date
and the next ensuing due date for the payment of such real property tax or
assessment from six (6), and the denominator of which shall be six (6). The
aggregate of the amounts paid on account of each such real property tax and
assessment shall constitute the "Tax Escrow Account". The Tax Escrow Account
shall be supplemented, from time to time, within fifteen (15) days of Lessor's
demand, by the payment by Lessee into said Tax Escrow Account of such additional
sums so that Lessor shall, at all times, have available an amount sufficient, in
Lessor's reasonable estimate, to pay at least thirty (30) days before each six
(6) month installment of each such real property tax and assessment shall become
due, the installment so becoming due. In addition to, and not in substitution
of, the payments hereinbefore stated in this paragraph 27 to initially establish
the Tax Escrow Account, from and after the commencement of the term hereof,
Lessee shall pay to Lessor monthly in advance, an amount equal to one-twelfth
(1/12th) of the annual real property taxes and assessments (as the same may



                                     - 9 -
<PAGE>   10

be increased or decreased). If the amount of said monthly payments paid by
Lessee shall be less than the actual amount due, Lessee shall pay to Lessor the
difference between the amount paid by Lessee and the actual amount due within
ten (10) days after demand from Lessor. If at the end or expiration of the term,
there shall be a balance to Lessee's credit in the Tax Escrow Account, said
balance shall be refunded to Lessee, provided Lessee is not then in default and
has surrendered possession of the demised premises to Lessor in accordance with
paragraph 12 hereto. A tax bill submitted by Lessor to Lessee shall be
conclusive evidence of the amount of real property taxes or assessments assessed
or levied as well as the items taxed. Lessee at all times shall be responsible
for and shall pay, before delinquency, all municipal, county, state or federal
taxes assessed against any leasehold interest or any personal property of any
kind owned, installed or used by Lessee. Lessor shall have the sole, absolute
and unrestricted right to institute and settle any contest, proceeding or action
dealing with real property taxes and assessments affecting the demised premises
upon whatever terms Lessor may, in its sole discretion, determine. In the event
of any refund of real property taxes and assessments, Lessor shall, provided
Lessee is not then in default under any of the terms of this Lease, remit such
portion of the refund as shall be allocable to payments of taxes actually made
by Lessee, less costs, expenses and attorneys' fees incurred in obtaining such
refund.

      28. SECURITY SERVICES: Lessee acknowledges that Lessor is not providing,
and is not obligated to provide, any security protection services to the demised
premises, Buildings or Land.

      29. Intentionally deleted.

      30. WAIVER OF JURY AND COUNTERCLAIM: It is mutually agreed by and between
Lessor and Lessee that the respective parties hereto shall and they hereby do
waive trial by jury in any action, proceeding or counterclaim brought in the
Circuit Court of Fairfax County by either of the parties hereto against the
other on any matters whatsoever arising out of or in any way connected with this
Lease, the relationship of Lessor and Lessee, Lessee's use or occupancy of said
demised premises and/or any claim of injury or damage and any emergency
statutory or any other statutory remedy. Lessor and Lessee agree that in the
event of any litigation regarding this Lease, its terms and the enforcement of
the rights and obligations of the parties hereto, the sole proper venue for any
such litigation shall be in Fairfax County, Virginia.

      31. SECURITY: Lessee has deposited with Lessor the sum of Thirty-five
Thousand and 00/100 ($35,000.00) Dollars as security for the faithful
performance and observance by Lessee of the terms, provisions and conditions of
this Lease; it is agreed that in the event Lessee defaults in respect of any of
the terms, provisions and conditions of this Lease, Lessor may, without
prejudice to any other remedy which Lessor may have on account therefor,
appropriate, use, apply or retain the whole or any part of the security so
deposited to the extent required for the payment of any sum as to which Lessee
is in default and Lessee shall forthwith, upon demand of Lessor, restore said
security to the original sum deposited. Lessor may commingle the security
deposit with its other funds and no interest shall be payable to Lessee. In the
event that Lessee shall fully and faithfully comply with all of the terms,
provisions, covenants and conditions of this Lease, the security shall be
returned to Lessee after the date fixed at the end of this Lease and after
delivery of entire possession of the demised premises to Lessor. In the event of
a sale of the Land and Building or leasing of the Buildings, Lessor shall have
the right to transfer the security to the vendee or Lessee and Lessor shall
thereupon be released by Lessee from all liability for the return of such
security.

      32. VIRGINIA LAW: This Lease shall be governed by and construed in
accordance with the laws of, or applicable to, the Commonwealth of Virginia.

      33. BROKER: Lessee represents that the sole broker instrumental in
consummating this Lease was Bishopp Realty, Inc. (the "Broker") and that no
dealings or prior negotiations were had with any other broker concerning the
renting of the demised premises. Lessee agrees to hold Lessor harmless against
any claims for brokerage commissions, other than those made by the Broker,
arising out of any conversations had by Lessee with any broker other than the
Broker.

      34. RECORDING: Lessee shall not record this Lease or a memorandum thereof
without the written consent of Lessor.

      35. Intentionally deleted.

      36. Intentionally deleted.

      37. WAIVER OF LIABILITY: The term "Lessor" as used in this Lease shall
mean only the owner, or the lessee of a lease, of the Buildings or Land, or
their respective mortgagees


                                     - 10 -
<PAGE>   11

in possession, so that in the event of any future transfer of title to the
Buildings or any assignment of lease by Lessor, or lease by Lessor of the
Buildings or of the Land and Buildings, the entity so transferring, assigning or
leasing shall be and hereby is entirely freed and relieved of all covenants and
obligations of Lessor hereunder, and it shall be deemed and construed as a
covenant running with the Land without further agreement between the parties and
their successors in interest, or between the parties and any such transferee,
assignee or lessee, that the said transferee, assignee or lessee has assumed and
agreed to carry out any and all covenants and obligations of Lessor hereunder.
Lessee agrees to look solely to the estate and interest of Lessor in the Land
and Buildings, and subject to prior right of any mortgage of the Land and/or
Buildings, for the collection of any judgment (or other judicial process)
recovered against Lessor based upon the breach by Lessor of any of the terms,
conditions or covenants of this Lease on the part of Lessor to be performed, and
no other property or assets of Lessor shall be subject to levy, execution or
other enforcement procedures for the satisfaction of Lessee's remedies under or
with respect to either this Lease, the relationship of Lessor or Lessee
hereunder, or Lessee's use and occupancy of the demised premises.

      38. RIGHT OF LESSOR TO DISCHARGE OBLIGATIONS OF LESSEE: If Lessee shall
fail to perform or observe any of the terms, obligations or conditions contained
herein on its part to be performed or observed hereunder, within the time limits
set forth herein, Lessor may, at its option, but shall be under no obligation to
do so, perform or observe the same and all costs and expenses incurred or
expended by Lessor in such performance or observance shall, upon demand by
Lessor, be immediately repaid to Lessor by Lessee together with interest thereon
at the higher of eighteen (18%) percent per annum or one hundred twenty (120%)
percent of the prime rate charged by Citibank, N.A. (or if both rates be
illegal, at the maximum rate permitted by law) to the date of repayment. For the
purposes of this Lease, the term "prime rate" shall mean the rate then being
charged by Citibank, N.A. to its largest corporate customers for unsecured loans
of ninety (90) days or less.

      39. Intentionally deleted.

      40. BINDING ON SUCCESSORS, ETC.: Except as otherwise provided in this
Lease, the covenants, conditions and agreements contained in this Lease shall
bind and inure to the benefit of Lessor and Lessee and their respective legal
representatives, successors and assigns.

      41. LATE CHARGE: Lessee shall pay to Lessor a one-time (as opposed to
monthly) late charge of ten (l0 cents) cents per dollar for each installment of
base annual rent, any item of additional rent or other charge payable hereunder
which Lessee has failed to pay to Lessor within ten (10) days of Lessor's
written demand, not as a penalty, but to help defray administrative and other
expenses involved in handling delinquent payments. In the event any check given
to Lessor by, or on behalf of, Lessee is returned to Lessor by its bank for
insufficient funds or for any other reason or is otherwise uncollectible, Lessee
shall pay to Lessor a service charge in the sum equal to the higher of (i) Ten
and no/100 ($10.00) Dollars for each check so returned or otherwise uncollected
or (ii) one (1 %) percent of the amount of the check so returned or otherwise
uncollected, which service charge, if applicable and if not prohibited by law,
shall be in addition to, and not in substitution of, any "late charge".

      42. ATTORNMENT: If Lessor's interest in this Lease or demised premises or
the Buildings is encumbered by a mortgage and such mortgage is foreclosed, or
Lessor's interest in the ground lease, the demised premises or the Buildings is
acquired by deed in lieu of foreclosure or if Lessor's interest in this Lease,
the demised premises or Buildings are sold pursuant to such foreclosure or by
reason of a default under said mortgage, then notwithstanding such foreclosure,
such acquisition by deed in lieu of foreclosure, such sale, or such default (i)
Lessee shall not disaffirm this Lease or any of its obligations hereunder and
(ii) at the request of the applicable mortgagee, transferee by deed in lieu of
foreclosure or purchaser at such foreclosure or sale, Lessee shall attorn to
such mortgagee, transferee or purchaser and execute a new lease for the demised
premises for the rentals reserved herein and otherwise setting forth all of the
provisions of this Lease except that the term of such new lease shall be for the
balance of the term of this Lease.

      43. EXECUTION OF LEASE: The submission of this Lease for examination does
not constitute a reservation or option of any kind or nature whatsoever on or
for the demised premises or any other space within the Buildings and shall vest
no right in either party. This Lease shall become effective as a lease only upon
execution and legal delivery thereof by the parties hereto. This Lease may be
executed in more than one counterpart, and each such counterpart shall be deemed
to be an original document.

      44. MORTGAGEE PROTECTION CLAUSE: Lessee agrees to give any mortgage and/or
trust deed holders whose name and address has theretofore been provided in


                                     - 11 -
<PAGE>   12

writing to Lessee, by certified mail, a copy of any notice of default served
upon Lessor. Lessee further agrees that if Lessor shall have failed to cure such
default within the time provided for in this Lease, then the mortgagees and/or
trust deed holders shall have such additional time as may be necessary to cure
such default (including, but not limited to, completion of foreclosure
proceedings if necessary to effect a cure), in which event this Lease shall not
be terminated while such remedies are being so pursued.

      45. MISCELLANEOUS: A. Lessor, at its sole cost and expense, reserves the
right to: (a) change the street address and name of the Buildings; (b)
resubdivide the Land or to combine the Land with other lands, provided such
subdivision or combination does not adversely affect Lessee's use of the demised
premises or the parking area or increase Lessee's obligation to pay real
property taxes and assessments; (c) create easements over the Land and Buildings
and in the entrances, aisles and stairways therein or in any parking areas for
utilities, telephone lines, sanitary sewer, storm sewer, water lines, pipes,
conduits, drainage ditches, sidewalks, pathways, emergency vehicles, and ingress
and egress for the use and benefit of others, without Lessee joining in the
execution thereof and this Lease shall automatically be subject and subordinate
thereto provided the same do not materially, adversely affect Lessee's use of
the demised premises; and (d) alter the site plan, landscaping, walkways and
common areas outside the Buildings within the context of general site
improvements, provided the same do not materially, adversely affect Lessee's use
of the demised premises or parking area. Exercise of any such right shall not be
considered a constructive eviction or a disturbance of Lessee's business or
occupancy, provided Lessee's business operations and use of the parking areas
are not materially, adversely affected thereby.

      B. Unless specifically provided otherwise in this Lease, where Lessor's
consent or approval is required (whether under the terms of this Lease or
pursuant to any rule or regulation now existing or hereafter promulgated by
Lessor as hereinafter provided), Lessor may withhold or delay such approval or
consent in its sole discretion and without justification.

      46. PARTIAL INVALIDITY: If any provision of this Lease or application
thereof to any person or circumstance shall to any extent be invalid, the
remainder of this Lease or the application of such provision to persons or
circumstances other than those as to which it is held invalid shall not be
affected thereby and each provision of this Lease shall be valid and enforced to
the fullest extent permitted by law.

      47. HOLDING OVER: Any holding over after the expiration of the term or any
validly exercised renewal term shall be construed to be a tenancy from month to
month at the rent equal to 125% and additional rentals and other charges
specified herein plus one-twelfth (1/12th) of the annual real property taxes and
assessments and shall otherwise be on the terms herein specified so far as
applicable.

      48. ESTOPPEL CERTIFICATE: Lessee agrees, at any time, and from time to
time, upon not less than ten (10) days prior notice by Lessor, to execute,
acknowledge and deliver to Lessor, a statement in writing addressed to Lessor or
such other party as Lessor shall designate certifying that this Lease is
unmodified and in full force and effect (or, if there have been modifications,
that the same is in full force and effect as modified and stating the
modification), stating the dates to which base rent, additional rent and other
charges have been paid, the amount of security deposited, if any, and stating
whether or not there exists any default in the performance of any covenant,
agreement, term, provisions or condition contained in this Lease, and, if so,
specifying each such default and containing such other information, items and
certifications as Lessor shall request, it being intended that any such
statement delivered pursuant hereto may be relied upon by Lessor and by any
purchaser, mortgagee or prospective mortgagee of any mortgage affecting all or
any portion of the demised premises and by any lessor under a ground or
underlying lease affecting all or any portion of the Land or Buildings.

      49. FINANCIAL STATEMENTS: Lessee hereby agrees to annually furnish Lessor,
within ninety (90) days of the end of each of its fiscal years, with such
audited financial statements of Lessee as Lessor shall require in order to
reasonably determine the financial condition of Lessee. Such statements shall be
prepared by an independent certified public accountant and shall include,
without limitation, Lessee's net worth statements and statements of financial
position and retained earnings statement of Lessee and its subsidiaries, if any,
for the preceding three (3) years.

      50. HAZARDOUS MATERIALS: Lessee covenants and agrees, at its sole cost and
expense, to (i) indemnify, protect and save Lessor harmless against and from any
and all damages, losses, liabilities, obligations, penalties, claims,
litigation, demands, defenses, judgments, suits, proceedings, costs,
disbursements or expenses (including, without limitation, attorneys' and
experts' reasonable fees and disbursements) of any kind or of any nature


                                     - 12 -
<PAGE>   13

whatsoever (collectively, the "Indemnified Matters") which may at any time be
imposed upon, incurred by or asserted or awarded against Lessor and arising from
or out of any Hazardous Materials (as hereinafter defined) on, in, under or
affecting all or any portion of the demised premises and which presently exist
or hereafter occur (or the predicate or basis for which presently exists or
hereafter occurs) during the term of this Lease (other than for such
contamination or pollution that occurred off the Land but, through no fault of
Lessee or anyone claiming by, under, or through Lessee, emanates onto the Land)
or which otherwise results from, or out of, or is occasioned by, Lessee's acts
or omissions heretofore occurring or hereafter occurring during the term of this
Lease and (ii) promptly, upon Lessor's demand, (y) remove, or cause to be
removed, from the demised premises and properly dispose of, all Hazardous
Materials and (z) undertake and complete all remediation. As used herein,
"Hazardous Materials" means petroleum products and any other hazardous or toxic
materials, wastes and substances which are defined, determined or identified as
such in any Laws (as hereinafter defined) or materials which are required by any
Laws to be encapsulated or removed from the demised premises or any surrounding
area. As used herein, "Laws" means any laws, rules or regulations (whether now
existing or hereafter enacted or promulgated) promulgated, imposed or enacted by
any Federal, State or local government or governmental entity, unit, department,
agency or authority and any judicial or administrative interpretation thereof,
including any judicial or administrative orders or judgments.

      Indemnified Matters shall include, without limitation, all of the
following: (i) the costs of removal of any and all Hazardous Materials from all
or any portion of the demised premises or any surrounding areas, (ii) additional
costs required to take necessary precautions to protect against the release of
Hazardous Materials on, in, under or affecting the demised premises into the
air, any body of water, any other public domain or any surrounding areas and
(iii) costs incurred to bring the demised premises and any surrounding areas
into compliance with all applicable Laws with respect to Hazardous Materials.
All removal work referred to in clause (i) above, all work and other actions to
take precautions against release referred to in clause (ii) above and all work
and other actions performed in order to comply with Laws referred to in clause
(iii) above are herein collectively referred to as "Corrective Work."

Lessor's rights under this paragraph 50 shall be in addition to all other rights
of Lessor under this Lease.

      51. EXTENSION TERM: a. Provided Lessee is not in default under this Lease
at the time of the exercise of the within applicable option, Lessee shall have
the right to extend the term of this Lease for one (1) extension period (herein
referred to as the "Extension Term"), which Extension Term shall be for a period
of five (5) years and shall commence on the expiration date of the initial term
provided the initial term of this Lease shall not have been theretofore
terminated). The within described option shall be exercisable only in the
following manner: Lessee shall, no later than one (1) year prior to the
expiration date of the initial term of this Lease, give to Lessor written notice
of Lessee's election to extend this Lease on the terms, covenants, conditions
and agreements as hereinafter provided in Section 51b. In the event of the
failure of Lessee to give notice in accordance herewith, Lessee's right to
extend shall be conclusively deemed to have been waived and the term shall not
be extended beyond the then established expiration date provided for under this
Lease. At the request of either party following the exercise of the option to
extend, both parties agree to execute a confirmatory instrument confirming the
extension and the newly extended expiration date. Following the exercise of the
option to extend for the Extension Term, there shall be no further right on the
part of Lessee to further extend this Lease. The parties agree that the
limitations upon the exercise by Lessee of the option to extend shall be deemed
of the essence.

      b. The Extension Term shall be on the same terms, covenants and conditions
as the term of this Lease except that there shall be no right to renew this
Lease beyond the Extension Term, and the base rent payable for the first lease
year of the Extension Term shall be the fair market base rent for the first
lease year of the Extension Term (but in no event shall the base rent ever be
less than the base rent payable for the last lease year of the initial term),
and commencing with the first day of the second lease year of the Extension
Term, and continuing on the first day of each lease year thereafter, base rent
shall be increased by three (3%) percent of base rent payable for the preceding
twelve (12) month period.

      c. The base rent paid or payable by Lessee for the first lease year of the
Extension Term shall be determined as of the first day of the Extension Term
(which date is hereinafter referred to as a "Rental Recomputation Date"). In
this regard, no earlier than one hundred eighty (180) days and no later than
ninety (90) days prior to the Rental Recomputation Date, which ninety (90) day
period is hereinafter referred to as the "Exchange Period", Lessor and Lessee
will each submit to the other a statement of their respective determinations of
the fair market base rent for the demised premises for the first lease year of
the Extension Term (which period is


                                     - 13 -
<PAGE>   14

hereinafter referred to as the "Recomputation Period"), which statements shall
show how their respective determinations were derived.

      d. In the event that after the exchange of the statements as above
provided, the parties cannot agree on the fair market base rent for the first
lease year of the Recomputation Period, then the parties shall (within fifteen
(15) days after the last of the statements were exchanged, but in no event more
than fifteen (15) days subsequent to the Exchange Period) meet and attempt to
agree on the fair market base rent for the first lease year of the Recomputation
Period. If the parties hereto cannot (within ten (10) days of their first
meeting, but in no event later than thirty (30) days subsequent to the Exchange
Period) agree on the fair market base rent for the first lease year of the
Recomputation Period, they shall attempt to agree on a referee to determine the
matter. The referee must be a member of the Appraisal Institute with at least
ten (10) years of commercial appraisal experience in Fairfax County, Virginia.
If the parties hereto cannot agree on the appointment of a referee within
forty-five (45) days subsequent to the Exchange Period, either party may request
that the commercial real estate panel (or equivalent) of the American
Arbitration Association in the County of Fairfax (the "AAA") appoint a referee
meeting the foregoing requirements who has not represented, or provided any
services to, and is not then representing or providing any services to, either
Lessor or Lessee or any party related to either of them. If the AAA shall refuse
to appoint such referee or if the AAA shall then no longer be in existence,
either party hereto on behalf of both, may apply to the appropriate court of
competent jurisdiction in the County of Fairfax for the appointment of such
referee, and the other party shall not raise any question as to the Court's full
power and jurisdiction to entertain the application and make such appointment.
The referee shall review each of the statements of valuation (and how each
valuation was arrived at by Lessor and Lessee) and meet with representatives of
Lessor and Lessee with respect to each of such valuations. The referee shall
attempt to get the parties to agree on a valuation of fair market base rent for
the first lease year of the Recomputation Period, but if such parties do not
(within thirty (30) days of the referee's appointment) reach agreement as to
such value, the referee may, subject to the terms and conditions contained in
this paragraph 15d and on his own, determine the fair market base rent for the
first lease year of the Recomputation Period, which determination shall be
binding on each of the parties hereto. The referee's sole discretion in
determining the matter shall be limited to selecting one of the fair market base
rent valuations, originally submitted by the parties hereto during the Exchange
Period. In other words, the referee cannot submit an independent valuation of
his own, but must determine the matter solely on which fair market base rent
valuation for the first lease year of the Recomputation Period submitted by each
of the parties hereto during the Exchange Period more closely conforms with his
valuation of fair market base rent for the first lease year of the Recomputation
Period.

      d. In the event the fair market base rent for the first lease year of the
Recomputation Period is not determined by agreement between the parties hereto
or by decision of the referee, whichever may be applicable, by the Rental
Recomputation Date, then Lessee shall pay base rent in an amount equal to the
base rent payable by Lessee for the last lease year of the initial term, and if
the fair market base rent for the first lease year of the Extension Term is
thereafter determined to be greater than that number, (i) the base rent shall be
retroactively adjusted (based on the fair market base rent determined by the
parties hereto or by decision of the referee, as the case may be) to the Rental
Recomputation Date, (ii) Lessee shall (within ten (10) days of Lessor's written
demand therefor) pay to Lessor the "Differential", as such term is hereinafter
defined, and (iii) commencing on the first day of the month following the month
in which such demand for payment of the Differential was made by Lessor, Lessee
shall start making monthly installments of base rent in the recomputed amount
based on the fair market base rent for the first lease year of the Recomputation
Period determined by agreement between Lessor and Lessee or by decision of the
referee, as the case may be. For the purposes of this paragraph, the term
"Differential" shall mean the excess of (a) the applicable fair market base rent
for the first lease year of the Recomputation Period determined by agreement of
the parties hereto or by decision of the referee, as the case may be, for the
period between the Rental Recomputation Date and the last day of the month in
which Lessor's demand for the payment of the Differential was made by Lessor
(which period is hereinafter referred to as the "Interim Period") over the base
rent paid by Lessee for the Interim Period.

      f. Notwithstanding anything hereinbefore contained to the contrary, the
length of the term for the valuation of fair market base rent for the first
lease year of the Recomputation Period shall be the length of term that
maximizes the base rent then negotiable in the market and the valuation shall
give appropriate consideration to the location and size of the demised premises
and shall be based on best use of the demised premises.




                                     - 14 -
<PAGE>   15



      IN WITNESS WHEREOF, we have hereunto set our hands and seals the day and
year first above written.





                                        JAGUAR II, LC


                                        By:     /s/ Charles P. Cocke
                                           ------------------------------
                                        Name:   Charles P. Cocke
                                             ----------------------------
                                        Title:  Manager
                                              ---------------------------



                                        SENSYS TECHNOLOGIES INC.


                                        By:     /s/ R. R. Bower
                                           ------------------------------
                                        Name:   R. B. Bower
                                             ----------------------------
                                        Title:  V.P. Finance, CFO
                                              ---------------------------


                                     - 15 -
<PAGE>   16


                                   SCHEDULE I

<TABLE>
<S>           <C>
4             Office Trailers
1             4.7 Meter Satellite Dish Antenna, Pedestal and Associated Equipment
1             10 Meter Satellite Dish Antenna and Associated Structure and Equipment
Lot           Miscellaneous Roof Mounted Antennas
1             EMI Enclosure (Screen Room) and Associated HVAC System
2             Standby Power Generators and Associated Switches
2             Power Generators
1             Environmental Test Chamber, Power Transformer and Associated Equipment
1             Vibration Test Machine, Chamber and Associated Equipment
1             Air Compressor and Associated Air Lines and Hoses
1             Machine Shop Air Handling and Ventilation System and Associated
              Ductwork, Hoods, Fans, Etc.
1             Telephone Switch (PBX) and Associated Telephone Equipment
6             Mezzanine Platform Sections and Associated Stairs, Railings, Parts
1             Retractable Antenna Tower
1             Test Laboratory HVAC System
2             Vault Doors
Lot           Vault EMI Filters
Lot           Wire Screen Panels
1             UPS (Uninterruptable Power Supply) System
2             RF Anachoic Chambers, Pedestals and Associated Equipment
Lot           Security Alarm System, Sensors, Panels and Associated Items
Lot           Card Access Door System, Readers and Latches and Associated Items
Scaffolding to roof
All exterior storage buildings
Frames, piping, wiring test strands, etc. used in connection with Lessee's
operations and not needed for operation of any Building's mechanical systems,
including, without limitation, any of the foregoing strung, attached or running
along the exterior or interior walls, yards or roofs.
</TABLE>

                                     - 16 -
<PAGE>   17



                                    EXHIBIT A



PARCEL ONE (1), per Deed of Resubdivision and plat entitled "Plats showing
Resubdivision of Parcel "B", Subdivision of the land of L.S. Sorber and Co.,
Parcels Two and Three of the land of Tectonics, Incorporated", dated May, 1985
made by John P. DiGiulian, certified land surveyor, and recorded in Deed Book
6246, at page 907, among the land records of Fairfax County, Virginia.








                                     - 17 -