Invisible and yet safe. The concealed Olympia window contact is mounted in your window frame and is therefore, unlike conventional magnetic contacts, invisible from the inside and outside. The flat design fits into all common DIN frames and prevents optical impairment, especially of wood or colored art frames. The safe magnet contact technology provides for a reliable release of the alarm with unauthorized opening of windows in tilted position. When the battery level is low, a warning message is sent to the control panel.