2 Beams Photoelectric Beam Detector, Interdictions-beam sensors, photoelectric detector, Beam Detector, outdoor distance 80meter YK-QH2-80 2 Beams Photoelectric Beam Detector, Interdictions-beam sensors, photoelectric detector, Beam Detector, outdoor alarm distance 80meter outdoor alarm sensor ,photoelectric beam detector, photoelectric detector Characteristic:1, Wired, wireless, Wired/wireless ...