The Wireless Fence Transmitter can be used to expand the limits of your existing IF-300 The Wireless Fence Transmitter can be used to expand the limits of your existing IF-300 PetSafe Wireless Instant Fence Pet Containment System, For use with the IF-300 Pet safe wireless pet containment system, Extra transmitter will allow you to double your coverage area, Covers an adjustable circular area up to 1/2 acre (180" in Diameter), Completely wireless and portable, Includes: AC power adapter, Collar Material: Synthetic, Dimensions: 13"" D x 11, 75"" H x 9, 5"" W, SKU: GVDS632