A magnet & reed switching sensor for burglar alarms normally to be recessed into doors or windows & their frames. One part contains the magnet while the other part contains the reed switch which is normally closed in the presence of the magnet. Opening the doorwindow will cause the reed to open. The reed switch terminates in a pair of screw terminals & there are a further three terminals for the security loop. Operating distance reed to magnet Reed closes at 13mm & opens at 15mm.
Dimensions magnet or reed Length 35mm width 22mm. Requires a recess at rear in door or frame 19mm diameter 34in. by 15mm deep. Fixing centres 27mm. Screws supplied. Conforms to BS4737.