Protect your PetSafe dog fence system from lightning surges and spikes. Lightning strikes even miles away can create powerful surges or spikes which may damage your electronic in-ground fence. In nearly every case damage to the transmitter results from power surges or spikes traveling through the boundary wire and not the power adapter. This protector is designed to protect your PetSafe In-Ground Fence from surges or spikes that can reach it via your AC power connection and/or your buried boundary wire. Trust PetSafe to help keep your pet healthy safe and happy.