Abstract: Access-limiting apparatus comprising a body through which an access passageway is formed. A second passageway is formed in the body at a position intersecting the access passageway and a lock plate is slidably movable in the second passageway to a locked position closing the access passageway. Locked means on the lock plate and the body cooperate to secure the lock plate in the locked position. A key plate which is matched with the lock plate is provided with lock release means operable to engage the lock means so as to release the lock plate from the body.