Designed with self-tightening mechanism, this chuck enables you to simply loosen the chuck with a wrench, and install the grinding head or shaft. You can save time and efcompatiblet to improve your work efficiency with this self-tightening chuck, as it is easy to install. Made of high-quality brass and aluminum alloy material, the drill chuck has high strength, wear resistance, and long durability. Adopting anti-slip texture, the chuck can be conveniently tightened with hand. The chuck can clamp most shank tool like drill bits, which is suitable compatible drilling, polishing and grinding. Item Name: Drill Chuck Material: Brass,Aluminum Alloy Features: Self-Tightening, High Strength, Wear-Resisting Size Details: Clamping Diameter: A: 2.35mm/0.09", B: 3.175mm/0.13", C: 2mm/0.08" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Drill Chuck 1 x Central Shaft 1 x Hex Wrench