Made of high quality alloy steel (chrome-molybdenum)Tested to the highest specifications to deliver outstanding performance at the competitive cost Includes Male and Female sizes Packaged in a blow molded storage case Lifetime WarrantyGrey Pneumatic impact sockets are designed for professional tool users. They are engineered specifically for use with impact tools using the most up to date industrial specifications. This socket set contains the following: Male Sizes 3/16", 1/4", 9/32", 5/16", 11/32" and 3/8" ; Female Sizes 1/4", 9/32", 5/16", 11/32" and 3/8".