Door sensor is a magnetic switch composed of 2 magnetic parts and wireless signal emitter. It is widely used in security area to detect illegal open or movement of doors, windows and drawers, etc. UnGuard supplied door sensor has compact size and robust design with metal cover, suitable for any environment. By connecting with GPS tracker, it can detect the status of vehicle doors, windows and bonnets. GPS Tracker UT04 at most connect 3 door sensors, GPS tracker UT01 at most connect one doors sensor.