Wireless radio-fence containment system for pets weighing 8 pounds or more. Covers an adjustable circular area of up to a 1/2 acre (180-foot diameter). Receiver delivers safe static correction when pet strays into warning zone. Waterproof receiver collar uses 6-volt battery; setup and training manual included. Transmitter measures 8-1/2 by 9 by 9 inches; receiver measures 1 by 2 by 1 inches.