Specifications: Using premium quality copper and high speed steel material, they are very durable and practical to use. This set will allow you to get into those tight spaces much easier, it is a nice set for your handyman. It is suitable for manual drilling of wood, bone horns, amber, olive pits, walnuts, plastics and other materials. Item Name: Drill Bits Set Material: Copper, High Speed Steel Clamping Range: 0.3cm - 3.4cm Twist Drill Bits Specifications (10Pcs): 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm Twist Drill Bits Specifications (20Pcs): 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1.0mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm Features: Drilling Tools, Durable, Portable, Multifunction Copper Bit Holder Length: 10cm/3.94" (Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Copper Bit Holder or 1 x Copper Bit Holder 10 x Twist Drill Bits or 1 x Copper Bit Holder 20 x Twist Drill Bits