Shutter sensor is a pair of sensor which is the most reliable sensor in security fields used to detect the opening and closing of Shutter.It works on the principal of normally closed.(NC ) circuit.The wired part of the sensor can be fitted in Ground While the wireless part to be fitted with the movable part. When the gap between these two parts exceed from 30 to 40 mm, It works and give signal to control panel to raise alarm in armed condition.