Standard-Wireless-PIR-Sensors-Twin-Pack-Friedl&-DC44-Ideal-for-protection-of-large-rooms-hallways-&-landings-with-detection-range-of-up-to-12-metres-Once-movement-is-detected-signal-is-sent-to-alarm-system-Compatible-with-the-Standard-433 M Hz-Wireless-Alarm-Systems-with-control-panels-Friedl&-Dc 44-Wireless-Standard-Pir-Twin-Pack