The Guardian® Underground Fence® is a smart, affordable way to keep your pet safe and secure in your yard. Set your pet's boundaries by laying a wire around your yard, bury the wire just below the surface, and attach it to the transmitter. Your pet will wear a special receiver collar (sold separately) that works with the transmitter to keep your pet within the boundary. The collar will deliver a warning tone as your pet approaches the boundary followed by a quick correction if he attempts to leave the area. 1-year warranty. UL listed. Imported.