The BS8418 compliant D-TECT X MKIII detectors all feature quad PIR sensor modules, stylish plastic IP65 fully tampered housings with a discreet internal antenna. Units accept 2 x 3 Volt CR123 batteries (not provided), 500m RF transmission range on 868MHz and individual code for pairing to the receiver. The receiver (GJD392) can be linked in its base form to 4 detectors and this can then be expanded up to 16 detectors, with the use of the GJD393 4-way expansion module. Due to the number of individual detector codes (in excess of 16M), multiple receivers can be used on any site.