6 mm & 6.35 mm & 8mm - Three different chuck heads to meet your different needs. High Quality - High speed steel chuck, durable, wear-resistant and stable performance. Convenience and Efficiency - High precision chuck, tight and stable clamping, improving work efficiency. Good Woodworking Accessories - The collet chuck adapter, fine workmanship, no burrs, easy to carry and quick to install. Wide Range of Applications - suitable for engraving machines, wood routers, trimmers, vertical routers, etc. Specification: Material: High speed steel (HSS) Clamping inner diameter: 6mm/6.35mm/8mm Chuck shank diameter: 10mm Warm Tips: 1. This collet chuck set is suitable for woodworking tools, but not for metalworking tools. 2. It is recommended to use a tool with a large shank diameter and a short cutting edge, too long a cutting edge will cause vibration. 3. If the tool jumps, it should stop working immediately, reinstall and tighten it, and then work again after sufficient contact. 4. The tool