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 lock