If you are looking for underground pet fence for your dog, then here is the one by pet safe. This Wireless Dog Fence works with the help of a radio transmitter. It restricts the movement of the dog within the marked boundary. In fact, it is a fenceless boundary. The wire is placed under the ground around the perimeter of a home and it carries the radio signals. The dog is made to wear a light weight receiver collar. The moment he gets close to the boundary, it emits radio signals and starts beeping. If the dog ignores the sound and tries to cross the boundary, he gets a mild shock. Don’t worry! It won’t harm your dog. After few attempts only, the dog learns to avoid the restricted area.