Switching light on and off with maximum precision in long passageways and corridors. Because all objects can be clearly detected. Thanks to ultrasonic technology, that's not a problem for the Dual US. Installed at a height of 2.5 – 3.5 metres, the presence detector identifies even the smallest of movements – no matter which walking direction they come from - in a detection zone of 3 x 20 m. But only there: the sensor reliably masks out persons in adjacent rooms. That makes it the perfect corridor sensor for office and admin buildings.