The Yale mortice sashlock 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 sashlock lock is best suited to work with wooden doors. This mortice sashlock 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 sashlock lock Yale 5 Lever Essentials Mortice Sashlock ideal for wooden doors that need a high level of security For ensured security, this lock offers security Available in a Brass finish, the mortice lock has a 2.5 Inch/64 mm backset Supplied with two standard Yale keys; additional replacement keys can be ordered from a locksmith When used with a British Standard nightlatch and with door handles, this mortice lock can be used on external doors.