PetSafe Compatible Electric Dog Fence Wire Surge Protector - Professional Grade | Universally Compatible for ALL Inground Dog Fence and Wireless Dog Fence Systems Specially designed for Pet Containment Systems using a boundary loop wire Helps Protect Not Only Your Dog Fence System, but Also Your Home's Internal Electrical System (From Lightning) 2 outlets on the Extreme Dog Fence Surge Protector allow for protection without losing use of an outlet Green LED light indicates protection is in place Easy installation! Installs in minutes