Feature:1. Suitable for drilling or lathe spindles that accept 3MT taper shanks. 2. Specially hardened key parts improve the durability of the drill chuck. 3. Self-locking keyless feature automatically increases grip, high reliability and stability. 4. High precision, suitable for high precision machining and long service life. 5. The method of use is simple, practical, and has a firm connection performance. Specification:Item Type: Self Tighten Drill Chuck Clamping Range: 1/32in -5/8in (1-16MM). Mount: JT6 mount Adaptor Size: Approx. 13 x 2 x 2.5cm / 5.1 x 0.8 x 1in Drill Chuck Size: Approx. 10 x 4.5 x 4cm / 3.9 x 1.8 x 1.6in Package List:1 x JT6 Drill Chuck1 x MT3-JT6 Adaptor