THIRD AMENDMENT TO LEASE

EXHIBIT 10.19

THIRD AMENDMENT TO LEASE

     THIS THIRD AMENDMENT TO LEASE (the “ Third Amendment ”) is entered into as of this 25th day of February, 2008, by and between PLYMOUTH PROPERTIES REALTY LLC, a Delaware limited liability company, with an address in care of Great Point Investors LLC, Two Center Plaza, Suite 410, Boston, MA 02108 (“ Landlord ”), and ZAREBA SYSTEMS, INC., a Minnesota corporation, with an address of 13705 26 ^th Avenue N., Suite 102, Plymouth, MN 55441-3644, formerly known as Water Instruments, Inc. (“ Tenant ”).

WITNESSETH:

     WHEREAS, Plymouth Properties Realty Corp., as landlord (“ Predecessor ”), and Tenant, entered into a Lease Agreement dated January 4, 2002, as amended by Amendment of Lease Agreement dated March 18, 2002, and by Amendment of Lease Agreement dated April 30, 2004 (the “ Second Amendment ”) (as amended, the “ Lease ”), whereby Tenant is leasing from Landlord approximately 6,895 rentable square feet of floor area (the “ Existing Premises ”) in the building commonly known as Annapolis Business Centre, 13705 26 ^th Avenue N., Plymouth, Minnesota (the “ Building ”); and

     WHEREAS, Landlord has succeeded to the rights of Predecessor, as landlord under the Lease; and

     WHEREAS, Tenant has changed its name from “Water Instruments, Inc.” to “Zareba Systems, Inc.”; and

     WHEREAS, Tenant and Landlord have agreed to extend the Term of the Lease for a period of thirty-eight (38) months commencing on February 1, 2008 and expiring on March 31, 2011; and

     WHEREAS, Landlord and Tenant desire to amend the Lease, upon the terms and provisions set forth herein, to extend the Term as set forth herein, and to make other modifications to the terms and provisions of the Lease.

     NOW, THEREFORE, in consideration of the mutual promises herein contained and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged by the parties hereto, Landlord and Tenant agree as follows:

     1. Capitalized terms not otherwise expressly defined herein shall have the meanings ascribed to them in the Lease. The term “ Lease ”, as used in the Lease shall include the Lease, as amended by this all amendments thereto, including this Third Amendment.

     2. (a) Tenant acknowledges that Predecessor has transferred its interest in the Lease, as landlord, to Landlord. As of November 1, 2004, all references in the

Lease to Predecessor and its address (including but not limited to Section 3(f) and Section 24 of the Lease) are hereby deleted and replaced with the following:

“Plymouth Properties Realty LLC
c/o Great Point Investors LLC
Two Center Plaza, Suite 410
Boston, MA 02108
Attn: Joseph A. Versaggi

with a copy to:

United Properties LLC
3500 American Boulevard West
Suite 200
Bloomington, MN 55431
Attn: Lisa Dongoske

Rent payments to be sent to:
(a) by regular mail to:

Plymouth Properties Realty LLC
14577 Collections Center Drive
Chicago, IL 60693

(b) by overnight mail to:

Bank of America Lockbox Services
14577 Collections Center Drive
Chicago, IL 60693”

          (b) All references in the Lease to “Water Instruments, Inc.” are deleted in their entirety and replaced with, “Zareba Systems, Inc.”

     3.  Term . Notwithstanding any provisions of the Lease to the contrary, the Term of the Lease shall expire on March 31, 2011.

     4.  Base Rent . Paragraph 3(a) of the Lease, last amended by paragraph 3 of the