Suitable for an accurate drilling & tapping, Perfect for the jwellery, craft and model maker. knurled grip for better hand use. Can also be held in drill chuck or lathe chuck. Capacity 0- 4 mm ( 0- 0.8mm, 0.8 - 1.3 mm, 1.3 - 3.1 mm, & 3.1 - 4.8 mm)