Features: Made of 45# steel, solid and durable to use. Good metal texture, comfortable surface, easy to clamp, so that the output torsion becomes larger. Beautiful and practical design of the surface convex and concave, so that before and after the set can effectively cope with and can reduce the shaking jacket. Self tightening keyless feature automatically increasing gripping force, high reliability, and stability. Widely used with various drill machines, milling machines, lathes, boring lathes and electric hand tools. Specifications: Material: 45# steel Accuracy: 0.002 Chuck Capacity: 1-16mm Chuck External Diameter: 48mm / 1.89inch Chuck Length: Approx. 100mm / 3.94inch Arbor Type: MT2-JT3 Arbor Length: Approx. 115mm / 4.53inch Total Length: Approx. 200mm / 7.87inch Weight: Approx. 1168g Package Included: 1 x Keyless Drill Chuck 1 x MT2-JT3 Arbor