Manufacturer page.

The Sense Pro PIR comes complete with driver, PIR sensor, cable and plug. The PIR sensor is discreetly located at the edge of the frame. The light is activated by movement and turns off automatically after a predetermined period of time to provide good energy savings.The sensor does not detect movement through walls or doors.The PIR sensor also has an adjustable daylight sensor, so you can choose not to turn on lighting when there is sufficient daylight. Sense PIR can act as a master, controlling up to 3 other Sense panels (slaves).Sense Opalprism PIR can be mounted on ceilings with visible T-rails without accessories and on ceilings with concealed T-rails with accessories.