Features 1、Made of premium quality alloy steel material. 2、With 3 styles for option, meets your various needs. 3、1/4 inch hex shank snaps easily into the power screwdriver. 4、Built-in spring, quick to install and release. 5、Conveniently convert your power screwdriver into drill. Specification Features: Made of premium quality alloy steel material. With 3 styles for option, meets your various needs. 1/4 inch hex shank snaps easily into the power screwdriver. Built-in spring, quick to install and release. Conveniently convert your power screwdriver into drill. Specifications: Material: Alloy + Steel Type: Drill Bit Extension/ Drill Bit Extension + 0.3-6.5mm Drill Chuck / Drill Bit Extension + 0.3-8mm Drill Chuck (Optional) Shank: 1/4" Drill Bit Extension Size: 60 * 24mm / 2.4 * 0.9in Package List: 1 * Drill Bit Extension Package List 1 * Drill Bit Extension