Deadbolt operated by key from either side. Deadbolt is brass with two hardened steel rollers and the throw is 16mm. The measurements are as follows: 63mm(A) lock come with 45mm(B) backset, 76mm(A) lock comes with 57mm(B) backset, 101mm(A) lock comes with 82mm(B) backset. 200 standard differs numbered 001-200. If you are choosing the master keyed lock then these are available in master, sub and grand master keyed