The YALE L22180 Monarch Sashcase has 48mm centres, 30.5mm backset, 50mm case depth, 124mm case height and has 25mm faceplate width. This lock is also known as the Monarch lock. It is fitted with an anti thrust snib, has a reversible latch, a double throw deadbolt that gives a 24mm bolt shoot and is ideally suitable for use in metal doors. HandingThe latch can be reversed by placing a screwdriver in the rear of the case directly behind the latch. Push the latch forward and rotate it to the opposite hand. OperationLocking Method – A. Lift lever to engage locking mechanisms and then one full turn of the cylinder to lock. One full turn of the key, then push down on the lever to unlock.