Details: * brand new and high quality. *Chrome vanadium alloy steel construction for strength and durability. *Overall quenching heat treatment, high hardness, chrome-plated rust-proof surface. *Very handy tool accessory that adds versatility to your sockets. *Designed For Use With Air Pneumatic, Electric Impact Wrenches And Ratchets. *Allows Greater Flexibility For All Sockets And Drive Tools. *Size (Approx.): 1/2" to 3/8"--(12.7mm square hole to 9.53mm square head) 3/8" to 1/4"--(9.53mm square hole to 6.35mm square head) 3/8" to 1/2"--(9.53mm square hole to 12.7mm square head) 1/4" to 3/8"--(6.35mm square hole to 9.53mm square head) *Main material: Chrome vanadium steel 50VB30 *Quantity: 4pcs Package Contents: 4*Socket Adapter Note: The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.