The Wireless PIR Motion Detector is from a Smoke detetor, PIR Motion Detector, Gas Detector, Water leakage detector and gsm alarm security manufacturer! The wireless PIR Motion Sensor PIR-100B is an INPUT DEVICE, the motion sensor works on the principle of sensing infrared energy (heat) emitting from an intruder"s body moving through a protected area.It is with internal Antenna and MCU inside.