The OSW12-M occupancy sensor uses ultrasonic sensing for maximum motion sensitivity and infrared sensing for highest lights OFF reliability. The sensor continually analyzes and adjusts to changing conditions. The OSW12-M occupancy sensor uses the latest microprocessor based technology which permits the detector to continually adjust and optimize its performance. The detector requires a 24 VAC OSPxx series power pack. By combining ultrasonic and infrared technology, the OSW12-M occupancy sensor provides excellent small motion sensitivity (US) and error immunity (IR). The mounting base, provided with the sensor, allows quick and easy mounting in corners, on wall or on ceilings. With ultrasonic and infrared sensing, this top-of-the-line sensor provides the highest-degree of immunity to false tripping. Auto-adapting circuitry fine-tunes delay settings for install and forget simplicity.