AIR four-beam detector 120 m with integrated Heater and Alignment tool. The new SB active infrared beams series includes two-beam and four-beam detectors, which generate an alarm when 1 or 2 beams are interrupted, ignoring birds, small animals, dead leaves, etc. They consist of two identical detector modules equipped with detector cells integrating both transmission and reception functions. These modules are installed facing each other over the distance to be protected providing a non-physical invisible detection zone.