This intellipet In-Ground Fence System allows owners to create an in-ground, hidden fence using an easy-to-install boundary wire. Dogs wearing the receiver collar receive a harmless, but effective electrical stimulus when they approach the boundary to remind them to stay in the designated area. Pet control system is water-resistant and lightweight Includes an adjustable collar receiver with replaceable 6-volt alkaline battery Wall mountable transmitter 500 ft of wire to surround approximately 1/2 acre Boundary training flags, two sets of collar probes and training guideThe intellipet In-Ground Fence System receiver can be used with dogs as small as 8 lbs. Covers areas up to 5 acres. For use with dogs older than 6 months.See the Specifications and Instructions tabs for more product details.