Awakingdemi Drill Bits,tHSS Twist Drill,150-piece Mini Twist Drill Bit Kit HSS Micro Precision Twist Drill 24 Sizes 0.4-3.2mm (150pc HSS twist) 150pc HSS twist drill bits in storage plastic case;Hss PrecisionTwist Drills Mini Micro Small Craft Hobby Jewellry. Twist kit that contains 24 sizes, meet all usage demands; high hardness, easy to store & carry. Those drill bits are made of high speed steel HSS. Great for electronics, crafts, jewelry, watch making;use with a power drill. For sizes: 0.4mm 0.5mm 0.6mm 0.7mm 0.8mm 0.9mm 1.0mm 1.1mm 1.2mm 1.3mm 1.4mm 1.5mm 1.6mm 1.8mm 2.0mm 2.1mm 2.2mm 2.3mm 2.4mm 2.5mm 2.6mm 2.8mm 3.0mm 3.2mm.