This Banham L2000 is self deadlocking, deadbolt night latch meaning when the door closes the lock will engage the deadlock and require a key to re-enter. Meaning the Banham is secure against potential sliding attacks on the mechanism. British Standard 3621, Patented and Insurance approved. Cylinder and key protected by patent. 6 pin drill resistant cylinder. Maximum security differs. Exclusive coded key registration systems. High security 10" striker plate on door frame. Saw resistant steel bolt. Self deadlocking.