The Yale PM550 5 lever mortice deadlocks offers a high level of security & are suitable for use on external timber doors. The deadbolt on the lock is locked or unlocked by key from either side. These deadlocks also have a 14 mm. anti-saw deadbolt & are recommended for use on a front door in conjunction with a Yale BS nightlatch. A deadlock has a single deadbolt which is locked or unlocked & locked by means of a key from either side whereas a sashlock has both a deadbolt & a latch which is operated from either side by a lever handles. The security level of mortice deadlocks or sashlocks ranges from 2-5 levers. The higher the number of levers the more secure the lock is. Finish: Polished Brass. Case
Size: 67 mm. x 70 mm. Backset: 45 mm. This is the measurement from the edge of the door to the centre of the keyhole.