Connects to any wired alarm panel, Both beams need 12v power, Set of two beams: transmitter / receiver. 

ABT-150 series designed for perimeter protection. These detectors adopt new patented compact design, durable structure,rated against dust, rain for both indoor and outdoor applications. Utilizing dual beams technology, the detector can provide reliable intrusion detection, and avoid false alarm which is caused by pets, animal or weather conditions. Included installation brackets for easy installation.