Material: Made of premium high carbon steel, precision manufactured, high strength, durable, smooth surface, rust-proof, corrosion-resistant and wear-resistant. Exquisite packaging: It consists of 4 cone drill bits and 4 claw drill bits, designed in different shapes to meet your daily work needs. Practical sizes: 10mm round handle, 4 different sizes including 1/4 cork knife (6mm), 3/8 cork knife (10mm), 1/2 cork knife (13mm), 5/8 cork knife (16mm). Feature: Generally designed for cutting oak corks, cutting predictable size holes, removing old nails and other woodworking openings for furniture, carpentry, etc. Wide use: Suitable for bench drills and hand drills, we recommend the use of bench drills for more stable operation and improved work efficiency.