High carbon steel set holds extremely small drill bits for intricate, detailed work. Suitable for craft, hobby, model-making, jewellery and watch-making. 3 collet sizes 0 – 0.8mm (0 – 1/32”); 0.8 – 1.5mm (1/32 – 1/16”); 1.5 – 2.5mm (1/16 – 3/32”). Knurled collet holder. 6.35mm (1/4”) shank.