StarSide 0.5-3mm Small Electric Drill Bit Collet Micro Twist Drill Chuck Set with Allen wrench 0.5-3mm Small Electric Drill Bit Collet Micro Twist Drill Chuck Set This 0.5-3mm twist drill chuck set is made of copper with excelent workmanshi.The collets can go with twist drill as a mini hand drill for ABS board,aluminium shet,paperboard drilling. Material:copper Set of 8