Powerful magnets hold any fastener securely Made of high quality steel (chrome-molybdenum); thorough and exact heat treatment insures the correct balance of strength and durability Great for use in impact or non-impact applications Packaged in a molded storage case Lifetime Warranty This set contains standard length, fractional and metric sizes along with extensions and universal joint. Each socket is thoroughly made with the correct balance of strength, durability and is tested to the highest specifications to deliver outstanding performance at the most competitive cost. Set contains the following: Fractional Sizes 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4"; Metric Sizes 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm. Also includes 3/8" x 3/8" universal joint and a 3" extension.