Forend Finish: Brass (Striking Plate Security box type, finished to match forend)
Case Size: 79.5mm x 111mm (3in)
Backset: 57.5mm This is the measurement from the edge of the door to the centre of the keyhole.
Centre: 57mm This is the measurement from the centre of the follower, which operates the handles, to the centre of the keyhole. In the UK this is commonly 57mm.