Interlogix DS924i Motion Sensor is a wireless, battery-powered motion detector designed for use in residential or light commercial applications. It uses passive infrared (PIR) technology to detect changes in infrared radiation caused by movement, and it can be programmed to send a signal to a security system control panel when it detects motion. The DS924i has a range of up to 1000 feet (305 meters) in open air, and it can be mounted on a wall or ceiling.