The ODS10 uses passive infrared (PIR) detection technology to monitor a room for occupancy through a segmented Fresnel lens. This specialized lens divides the field-of-view into sensor zones, When a person passes into or out of a sensor zone, the sensor detects motion and switches the lights ON, The lights will remain ON as long as there is an occupant moving through the sensor zones. Fits in standard wallbox and replaces single-pole wall switch. Gangable with other units, Presentation Mode feature for slide or film presentations allows push buttons to turn lights OFF and keep them OFF while the room is occupied.