Passive Infrared Motion Detector is a wall-mounted unit with wide-angle motion protection. It communicates with the control panel of your home security system using a wireless frequency. When set to High (HI) Sensitivity Mode, the PIR has a maximum range of 30 ft deep x 50 ft wide. The PIR’s pet-immune feature can be set to tolerate animals up 55 pounds so Fido or a curious squirrel doesn’t set off you home alarm system.