The Excel Hardware 76mm (3") Stainless Steel Bolt Through Tubular Mortice Latch NP is for use with internal door handles on backplate & door handles on rose. It has a standard case size of 76mm with 57mm backset. Itcan be used on new doors & as replacements for old, worn latches. It will accept a standard 8mm square spindle. This latch is made from zinc alloy & has a nickel plated finish. Other Variations The latch is also available with a 63mm case & this can be found in the related products.