Bolt contact for lock state monitoring for doors. Extremely practical thanks to the variably adjustable switching point. The integrated reed contact technology means that it is also suitable for external doors. Bolt and lock state plate contacts are usually installed in the vicinity of the lock state plate in the door frame. When the deadbolt is closed, they report the lock state status to the intrusion detection system. The system can only be armed once the door’s lock state latch is extended.