Feature 1This set of collet chuck contains 1 black cap and 6 sleeves of different size for various holding needs 2The black cap is made from carbon steel and sleeve of high standard brass for durability and good performance 3This collet chuck set provides fast chucking, simply unclamp one part, switch to a new part and reclamp 4Collet chuck would ensures strong clamping force and holds quite securely during working under correct conditions 5The black cap can be conveniently tighten with hands with the exclusive skid resistance designSpecification Description: This is a set of collet chuck that forms a collar around an object to be held and exerts a strong clamping force on the object when it is tightened. The collet can be squeezed such that its inner surface contracts to a slightly smaller diameter, squeezing the tool whose secure holding is desired. Features: This set of collet chuck contains 1 black cap and 6 sleeves of different size for various holding needs. The black cap is made from carbon steel and sleeve of high standard brass for durability and good performance. This collet chuck set provides fast chucking, simply unclamp one part, switch to a new part and reclamp. Collet chuck would ensures strong clamping force and holds quite securely during working under correct conditions. The black cap can be conveniently tighten with hands with the exclusive skid resistance design. Specifications: Material: Brass, carbon steel Color: As pictures show Black Cap Size: M8 x 0.75mm Collet Sleeves Size: 1mm, 1.6mm, 2mm, 2.4mm, 3.2mm, 3mm Package Includes: 6 x Collet Sleeves 1 x Cap