PM562 Hi-Security BS 5 Lever Mortice Deadlock 68mm 2.5in Polished Brass - Yale Locks 655620105025, The Yale PM562 British Standard 5 lever mortice deadlocks offer a very high level of security and are suitable for use on external timber doors. The deadbolt is locked or unlocked by key from either side. The PM562 series lock are recommended by insurance companies, kitemarked to BS3621: 2007 and has been approved by the police Secured by Design initiative. These deadlocks also have a 20mm anti-saw deadbolt, an anti-drill case and have a 15 year guarantee. A deadlock has a single deadbolt which is locked or unlocked and locked by means of a key from either side, whereas, a sashlock has both a deadbolt and 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.The Yale Locks YALPM562PB25 PM562 Hi-Security BS 5 Lever Mortice Dead Lock 68mm 2.5 inch comes in the following:Finish: Polished BrassCase Size: 6mm x 89mm (2.5 inch)Backset: 45mm This is the measurement from the edge of the door to the centre of the keyhole. Yale Locks PM562 Hi-Security BS 5 Lever Mortice Deadlock 68mm Polished Brass