Electronic Barking Dog Alarm Reliable 24-hour protectionProtection with none of the problems of owning a real dog Emits microwave signals so it can "see" through walls and detect someone approaching from up to 21 feet away. Kindly do not stand behind the unit while testing it, as the sensor picks up your own motion. Comes with a wireless remote control to allow you to arm/disarm the unit from a distance as well as sound a panic alarm in case of emergency Switch from the barking dog to alarm or chime. Please follow the instructions provided and read the Manual before use. Radar sensitivity is adjustable from 10-20 feet - Senses movement through walls, doors and glass to alert you of an arriving visitor