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 645mm 25 inchs are suitable for handles with a backset of 44545mm latches with a case size of 76mm 3 inches are suitable for handles with a 57mm backset