This HOMESAFE WIRELESS HOME SECURITY MOTION SENSOR can detect motion from up to 8 meters away and has 110 degree motion detection angle. It has a wireless radio frequency range of 300 feet. When triggered the RF signal activates the alarm. Uses one 9-volt battery (not included). Easily protect every window and door of your home This pricing is available ONLINE ONLY. Standard retail or in-store price is much higher.