20 Pcs Mini Micro Twist Drill Bits  0.3mm-1.6mm w/ Aluminum Hand Drill Keyless Chuck 20pc 0.3mm-1.6mm Twist Drill Bit.Material: High Speed Steel aluminum hand drill punch holes in plastic,wood. Great for crafts, jewelry, watch making Hand drill:Material: Aluminium Alloy.chuck Clamping Range:0.3-3mm