Made with chromium-vanadium steel forging, high strength and good wear resistance, durable to use. To prevent rust and corrosion, the phosphate finish absorbs and retains oil, repelling moisture. The spring ball lock ensures a tight fit with the driver head to prevent slipping during use. Can be firmly installed in a handheld driver, drill driver or impact wrench. Chamfered ends insert smoothly into fastener head, reducing wear. Wide application in DIY hand-making, household maintenance, and most general repairs.