Designed for use on small pad and arm screws. The finest quality tempered steel blades and free-spinning hexagon swivel heads to prevent rolling. Set of six optician’s screwdrivers includes one each: 0. 6 mm, 1. 0 mm, 1. 4 mm. , 1. 8 mm, 2. 0 mm, 2. 6 mm. 1 set.