The Yale 1109 series replacement rim cylinders are for use with surface mounted locks, such as nightlatches, operating from a tailbar. They are used to provide key access from one side of a door and are suitable for doors 38mm to 57mm in thickness. The tailbar can be cut to suit the thickness of the door.This Yale YALB1109PB Replacement Rim Cylinder comes in Polished Brass Keyblank No.8 Supplied with two keys Rim Finish: Polished BrassPack: Boxed