The "OSK-60mm Normal Knob" is a 60mm zinc-range mortice cylinder with a key on one side and a slim thumb-turn knob on the other, for fitting into a mortice door lock. It belongs to the Zinc Range of mortice cylinders, offered in sizes from 60mm to 100mm. The cylinder has a brushed silver-toned finish and a profile-shaped body with a black central cam and a threaded fixing-screw hole. The narrow, flat thumb-turn locks the door from inside, while the keyway at the other end serves the outside. Catalogue code: 37525