The built-in/surface-mounted opening detector is a magnetic contact with which you can secure doors and windows. Unauthorized opening is detected and reported to the alarm center. The built-in/surface-mounted opening detector consists of a magnetic contact (reed) and a magnet. These are installed either parallel, face-to-face or orthogonally to each other - at a distance of 13 to 25 mm. The circuit of this NC opening detector is closed in the idle state. If the distance between the reed and the magnet increases, the circuit is interrupted and an alarm is reported. The detector is protected against sabotage. The optimal installation location is the middle of your door or window frame. Installation on the lower window frame is also possible if a certain window is to be tilted when the magnetic contact is secured. The detector is suitable for both surface-mounted and flush-mounted installation. The opening detector is VdS certified and available in white and brown.