The wireless driveway alarm alerts you when a vehicle enters or exits your property. When a vehicle passes the sensor, the indoor receiver emits a chime. It has a wireless range of 400 ft (121.9 m) and will not be activated by people, animals or wind. The indoor receiver can be mounted on a table or on the wall. Multiple indoor receivers (up to 3) can be added for more convenience. Detects moving vehicles and not a motion sensor.