It is made from heat-treated hardened chrome-vanadium steel. Durable solid steel set designed to withstand torque compression under most standard use situations. The electroplating process of the adapter surface makes the power drill socket adapter set anti-rust. Features - ColorAssorted Color - Size: 5.80X1.50X1.50cm/2.28X0.59X0.59 inch. - Material: Chrome-vanadium steel. - This adapter set is designed to provide a securely extension to your existing . Provides additional length to reach into a multitude of hard to reach spaces. - The spring ball lock ensures a tight fit into the driver head to prevent slipping during use. - This bit driver extension adapter is designed to meet a variety of needs. Fits snugly and securely in your drill chuck or hand held driver. - Equipped with 1/4 inch, 3/8 inch, 1/2 inch impact driver adapters which use unique spherical design that distributes torque loads evenly over a greater surface area. - They also allow you use for reaching more narrow workplace. Package list: 2 sets x power drill socket adapters