Features PRACTICAL DESIGN: The collet has a full length slit that allows the collet to fold evenly, providing a concentric and 360 degree clamping surface. SPRING STEEL: These collets are made of excellent spring steel, with high temperature resistance, corrosion resistance, and stable performance. GOOD PERFORMANCE: After heat processing and cold drawing hardening, these spring steel collets have high strength, good flexibility and plasticity. APPLICABLE RANGE: Suitable for milling, drilling, tapping, engraving, etc., used in CNC center, milling machine, engraving machine, high speed machine, etc. INCLUDED TOOLS: Includes 4pcs spring collets with different diameters to meet more clamping needs, and equipped with a wrench for easy use. Specification: Item Type: Collet Set Material: Spring Steel Chuck Specification: Diameter 16 18 20 25 Wrench Specification: 38-42 Package List: 4 x Collets 1 x Wrench Package List 4 x Collets 1 x Wrench