Passive Infrared (PIR) Detector, auto switching on when detecting people coming, super sensitivity . Features *. Using 4PCS AAA batteries.*. Passive Infrared (PIR) Detector, auto switching on when detecting people coming, super sensitivity within 3-meter distance, 90 degree(angle).*. Wireless, easy to install, can be used in bedroom, washing room and on refrigerator, washer, iron door, exhaust ...