Drill Bit ExtensionLength: 60mm; Hex Shank Diameter: 1/4 inch (6.35mm); Hex Socket Diameter: 1/4 inch (6.35mm). Durable & StableMade of premium stainless steel for high strength and hardness, durable for long time. Easy to UseThis drill bit holder extension is non-magnetic! It has a built-in stability lock and high-efficiency spring. Excellent concentricity can greatly improve work efficiency. Quick Release Bit HolderInterface has a locking mechanism for one-handed quick release. Press down can release the ejection bit, realizing quick replacement in one second. Widely ApplicationHex shank can fit power drills chuck, 1/4-inch impact drivers and hand-held drivers. Used for screwdriver bits, drill, batch head and other tools for the conversion.