The opening detector is a magnetic contact for protecting doors and windows. Unauthorised opening is detected and reported to the alarm panel. The opening detector consists of a magnetic contact (reed) and a magnet. These are fitted parallel, in front of, or at right angles to each other at a minimum distance of 13 mm apart. The electric circuit of this NO opening detector is normally open (NO). If the distance between reed and magnet increases by ca. 2 cm, the circuit is closed and an alarm reported. The optimum installation location is the middle of the door or window frame. It can also be fitted to the bottom of the window frame if a particular window with a magnetic contact is to be tilted open. The detector is suitable for both flush and surface-mounted installation. The opening detector is available in white and brown.