The Halo USB Beacon uses Bluetooth to communicate with your dog’s Halo collar to convey how close your dog is to the Beacon. The USB Beacon can be plugged into the Halo Wall Charger (included) or other standard USB-A port to create keep-away or ignore-fence areas near wall outlets, computers, or other indoor locations with a USB or AC wall power. The USB Beacon turns on whenever connected to power, so it will ‘run forever’ as long as the power source has live power – so you don’t have to worry about changing batteries.