UNION StrongBOLT 22WCS Mortice Bathroom Lock Polished Brass 81mm 3″

Forend finish: Polished brass.
Case size: 81 x 109.6mm.
Backset: 57mm. 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.