Made from premium chrome vanadium steel, Impact drill chuck capacity: 0.06-0.5 inch/1.5-13mm; Mount Thread: 1/2-20UNF Classic keyed 3-jaw design with excellent clamping capability, securely holds a wide range of twist drills and step drill bits with 1/16 inch to 1/2 inch shank Standard 1/4 inch hex shank Chuck adapter could quickly connect to any impact driver and converts to drilling function Versatile use on impact drills and electric power driver to quickly switch tasks and keep the job moving, improve work efficiency. Please Note The product can NOT be used counterclockwise Must be transferred to 'hammer drill stalls', when you use the hammer chuck, other stalls will lead chuck broken Specification: color: as show Material: Chrome Vanadium steel (CR-V) Shank: 1/4 inch Hex Shank Clamping Range: 1.5-13mm (1/16-1/2 inch) Mount Thread: 1/2"- 20UNF Package Included: 1 x Drill Chuck 1 x Chuck Key 1 x 1/4-Inch Hex Shank