Designed to protect your In-Ground Fence from surges or spikes that can reach it via your AC power connection and/or your buried boundary wire The Surge Protector must be plugged into a grounded (3-prong) outlet that is within 5 feet of the Fence Transmitter Do not install device if there is not at least 30 feet (10 meters) or more of wire between the electrical outlet and the electrical service panel (breaker box/fuse panel).