EXHIBIT 10(l)


HELLER FINANCIAL


                                 March 26, 1997


Guardian International
3880 North 28 Terrace
Hollywood, Florida 33020-1118

Attention: Mr. Robert K. Norris

Dear Mr. Norris:

We refer to that certain Loan and Security Agreement dated as of November 16,
1994 (as amended, the "Loan Agreement") between Heller Financial, Inc.
("Heller") and Guardian International, Inc. ("Guardian"). Capitalized words and
phrases not otherwise defined in this letter will be used with the same meanings
given such terms in the Loan Agreement.

Section 6 of the Loan Agreement requires Guardian to maintain at all times a
Tangible Net Worth of not less than $1,450,000. For Guardian's fiscal year
ending December 31, 1996, Guardian's Tangible Net Worth was less than the
required amount. Guardian's failure to maintain its Tangible Net Worth at the
required level would permit Heller, under the terms of the Loan Agreement, to
declare an Event of Default and to accelerate all of the Obligations due to
Heller under the terms of the Loan Agreement. Guardian has requested that Heller
waive Guardian's non-compliance with the Tangible Net Worth test set forth in
the Loan Agreement for Guardian's 1996 fiscal year only. Heller is prepared to
accede to Guardian's request.

Therefore, this letter is to advise Guardian that for Guardian's 1996 fiscal
year only, Heller waives Guardian's non-compliance with the Tangible Net Worth
test set forth in the Loan Agreement. Nothing herein shall be construed by
Guardian as a continuing waiver of the Tangible Net Worth test set forth in the
Loan Agreement or as a continuing waiver of any other term or condition set
forth in the Loan Agreement. Except as expressly modified by the terms of this
limited waiver, the Loan Agreement remains in full force and effect.


<PAGE>

In an unrelated matter, it has come to Heller's attention that at the time of
the Second Modification, the Revolving Loan Commitment Termination Date was not
extended beyond November 30, 1996. It was Heller's intention at that time
(evidenced by the fact that from and after November 30, 1996 Heller has
continued to make advances to Guardian under the Revolving Loan) to extend the
Revolving Loan Commitment Termination Date to a later date. By its signature
below, Heller acknowledges and agrees that the Revolving Loan Commitment
Termination Date is December 31, 1997 effective as of the effective date of the
Second Modification. By its signature below, Guardian acknowledges and agrees
that the Revolving Loan Commitment Termination Date is December 31, 1997.

Please indicate your agreement with the foregoing by signing and dating a copy
of this letter in the space provided below and return a fully executed copy via
overnight courier to my attention at the address provided above.

Sincerely,

Heller Financial, Inc.

By:/s/ ROBERT J. DENNIS
   ----------------------------
   Robert J. Dennis

Title: EXECUTIVE VICE PRESIDENT
      -------------------------



Acknowledged and Agreed this 26 day of March 1997.

Guardian International, Inc.

By:/s/ RICHARD GINSBURG
   -------------------------
   Ricahrd Ginsburg

Title: PRESIDENT/CEO
      ----------------------