Contact NC: The circuit is closed when the door is closed. When the door opens, the circuit also opens and the alarm is triggered. It offers maximum security because it is activated even if the cable is cut.
Contact NO: The circuit is open when the door is closed. When the door opens, the circuit closes and the alarm is triggered. It is used only in special or older installations where the alarm panel requires it.
Metallic: Heavy-duty metal contact suitable for use on iron doors, shutters, garage doors, etc.
Tamper Protection: It refers to protection against attempts to tamper with the device. For example, if someone tries to open the sensor’s casing or remove it from its position, the sensor will send an alarm signal.