Chamberlain CWPIR Motion Alert System, 30 ft, 120 deg Detection

Wireless motion alert system detects motion up to 30 ft away with wide 120 deg coverage, transmits signal to base station up to a half-mile away. Sensor has adjustable sensitivity controls. Receiver indicates movement with light and sound, features adjustable volume controls. System includes one base station, one motion sensor, one AC adapter, mounting hardware and non-slip feet. Receiver is powered by an AC adapter (provided), four AA batteries enable battery backup mode. System can accommodate up to 4 sensors per base station. Sensor requires four AA batteries.