The Union 2648 mortice latches are suitable for timber doors hinged on the left or right and requiring lever handle operation. The latch is made of nylon for a quieter closing action. Please note these are not suitable for use with unsprung lever handles. Latches with a case size of 64.5mm (2.5 inchs) are suitable for handles with a backset of 44.5/45mm. Latches with a case size of 76mm (3 inches) are suitable for handles with a 57mm backset.