Features: Sturdy and Durable:Heat-treated chrome vanadium steel, anti-rust. Easy and Safe:Anti-slip, flexible. Mounted on a black clip, easy to use and storage. Extensive Use:Applicable for installing in those hexagon tools, such as a pneumatic screwdriver, electric screwdriver, pneumatic drill, electric drill, pistol drill, manual screwdriver, etc. Anti-shedding steel ball:Self-locking device is not easy to slip or fall off, better fixed. Double R slot design:Hex shank, double R slot design,more endurance. Various specifications:High-quality materials, various specifications, can be used with universal sleeves. Easy to Choose:Different colour coded rings, make it easy to pick the right one. Scope of application:It is used for installation on hexagonal tools such as pneumatic screwdrivers, electric screwdrivers, pneumatic drills, electric drills, pistol drills, manual screwdrivers, etc. Specification Material: Steel40CR tool steel(drill driver sleeve and Inner hexagon connecting rod ), Chromium vanadium steel CRV(Black connecting rod ) Color: Silver+black Sleeve size: About 3/16inch(4.76mm),1/4inch(6.35mm),9/32inch(7.14mm),5/16inch(7.93mm),11/32inch(8.73mm),3/8inch(9.53mm),7/16inch(11.11mm), 0.2inch/5mm,0.22inch/5.5 mm,0.24inch/6mm,0.28inch/7mm,0.3inch/8mm,0.4inch/10mm,0.47inch/12mm Connecting rod size: About 1/2inch(12.7mm), 3/8inch(9.5mm), 1/4inch(6.35mm) Connecting rod length: About 65mm/2.6inch, 73mm/2.87inch Connecting rod shank diameter: opposite side 6.35mm hexagonal shank, double R groove Inner hexagon connecting rod size(Dia x L): About 10 x 55mm/0.39 x 0.87inch Package included: 14pcs x Hexagon shank electric drill driver sleeve 3pcs x Black connecting rod 1pc x Inner hexagon connecting rod