Fast, wide-range, versatile sensor switch with high-frequency technology. As the flush-mounted version ideal for staircases, halls & bathroom. As the surface-mounted version ideal for staircases, cellar & laundry room. High-frequency detectors emit an imperceptible signal & respond, independently of temperature, to changes in the echo pattern that occur as a result of movement. With a wide angle of detection, almost instant response times, as well as a range that can be adjusted between 1 m & 8 m, this sensor switch is suitable for even complex room layouts.