The Union 2177 3 lever mortice deadlocks are ideal for timber doors hinged on the left or right and the keys are suitable for doors up to 54mm thick. The deadbolt is locked or unlocked by the key from either side, and has a 12.5mm anti-saw deadbolt. 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. Specifications Case Size: 77.5mm x 70mm (3in) Backset: 57mm This is the measurement from the edge of the door to the centre of the keyhole. Pack: Visi Case Steel, silver powder coat Forend Satin Chrome Striking Plate Finished to match forend Deadbolt Brass, with hardened steel rollers Rebate Kit 2969 (13mm, 19mm or 25mm) Keying Groups May be supplied to pass, differ and keyed alike with 2077,