Jacobs Keyless Drill Chuck 13MM For Hitachi Makita Dewalt Features: Product Type : Metal Double Sleeve With Lock Function 1/2" X 20 UNF Female Mount 1.5 - 13mm Drill Capacity Weight :11.6 OZ *Please note,anticlockwise screw NOT included Double sleeve chuck will suit drill without spindle lock. With audible click sound when chuck fully locked. with a hole in the rear for counterclockwise screw to lock it in the shaft. Professional high quality replacement chuck. Recommended for professional grade DC/AC rotary/hammer drills. Hardened steel, 3 heat-treated jaws bites reduce bit slippage and enhances wear resistance, even in the most demanding applications. Patented technology provides a positive locking mechanism which prevents loosening in hammer and other high vibration applications.