Wireless motion alert system detects motion up to 30 ft away with wide 120° 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 1 base station, 1 motion sensor, 1 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.