Petsafe PIF-300 Wireless 2-Dog Fence Containment System 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) Two dog system includes extra PIF-275 collar Receiver delivers safe static correction when pet strays into warning zone Waterproof receiver collar uses 6-volt battery; setup and training manual included