Very simply, a wire is installed around the perimeter of your property, establishing your pet's boundary. A transmitter, usually placed in your house or garage, sends a radio signal along the wire. The radio signal is picked up by your pet's receiver collar, which emits a warning sound when your pet approaches the boundary wire proper training is critical to ensure that your pet understands and stays within the established boundaries. During the training process, you will show your dog where they can and cannot go and after a period of time many owners no longer need to put the collars on the dogs as they learn not to leave the property.