Afavv will track the distance of your dog by sending out a repeating signal. Once that signal is too far from the Transmitter, the collar will first beep. This teaches your dog that they are going beyond the perimeter you set for them. If they keep moving past, the beeping increases until the collar gives a slight shock. If your dog is stubborn or hard of hearing then a shock will make sure they stop running and come back to the zone.