The Yale PM320 3 Lever mortice sashlocks offer a standard level of security and are suitable for use on internal timber doors. The deadbolt is locked or unlocked by key from either side. These sashlocks also have a 13mm anti-saw deadbolt, and has been designed for use with door furniture. 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 security level of mortice deadlocks or sashlocks ranges from 2-5 levers. The higher the number of levers the more secure the lock is.