The PM562 series lock are recommended by insurance companies, kitemarked to BS3621: 2007 and has been approved by the police Secured by Design initiative.
A deadlock has a single deadbolt which is locked or unlocked and locked by means of a key from either side, whereas, a sashlock has both a deadbolt and a latch which is operated from either side by a lever handles.
The deadbolt is locked or unlocked by key from either side.
