The Yale mortice Deadlock lock that meet all applications and security needs. A mortice lock is set inside the door itself to ensure a flush finish rather than being surface mounted. A mortice Deadlock lock is best suited to work with wooden doors. This mortice Deadlock is 5 lever. The greater number of levers in the lock the more secure your door will become. The most secure is a 5 lever mortice Deadlock lock About this item Mortice Lock: Yale B-BSDL-3.0-PB 5 Lever Mortice Deadlock ideal for wooden doors that need a high level of security Maximum Security: For ensured security, this lock offers a maximum level of security Colour and dimensions: Available in a Chrome finish, the mortice lock has a 3 Inch/76mm mm backset Keys Supplied: Supplied with two standard Yale keys; additional replacement keys can be ordered from a locksmith Suggested Use: When used with a British Standard nightlatch and with door handles, this mortice lock can be used on external doors