It's widely used in household DIY, auto parts, woodworking, professional machine repairing a professional contractor, etc. Six corners with groove design, can maximize to avoid the fastener scratch and wear in the using time. Universal 1/4 inch hex shanks fit quick-change/release and lock firmly in standard chucks, impact driver, drill driver and screwdriver. 18 Pcs Hex Shank Sockets, 5, 6, 7, 8, 9, 10,11, 12, 13 mm. Universal 1/4 inch. hex shanks fit quick-change chucks and any drill, driver, or screwdriver. Strong inner hexagon sleeve (non magnetic). Applicable for installing in those hexagon tools, such as pneumatic screwdriver, electric screwdriver, pneumatic drill, electric drill, pistol drill, manual screwdriver, etc. Forged and hardened chrome vanadium steel, Corrosion-resistant sandblasted finish. Anti rust and anti slip. Set Includes: 18 pcs. Power Nut Driver Bits (Metric): 5, 6, 7, 8, 9, 10, 11, 12, 13 mm. Complete with workbelt storage clip, easy to use and storage. Widely used in household DIY, auto parts, woodworking, professional machine repairing, etc. Color: Silver grey, black Materials: Chrome vanadium steel Package includes: 18 x Metric Nut Driver Bit Set