Designed for discreet reinforcement, the PM444 series Security Door Bolt from Yale Locks is concealed within the door (mortice fixed) and secures by throwing a bolt into the door frame. Operated with the supplied key, it provides an additional layer of security for external doors and other access points where extra protection is required. With its hidden fitting, this door bolt maintains a clean look while adding a dependable locking point that can be engaged when you want greater peace of mind at home. Key features Concealed, mortice-fixed door bolt design Bolt throws into the door frame for added security Key-operated mechanism Supplied with a key Model number: PM444 Please note: Colours shown are as accurate as possible, though may vary slightly depending on your screen settings.