The Socket Base ls Made of Heat Treated Chrome-Vanadium Steel, and the Bit ls Made of S2 Alloy Steel. Multiple sizes available for ease of use. High contrast and specific size marking for identification, It helps you select the size easier. It comes with a sturdy and convenient storage case, Keep each piece in the proper position. All products meet or exceed ANSI performance standards. The socket base is made of heat treated Chrome-Vanadium steel, and the bit is made of S2 alloy steel. Set Includes: Hex Bit Socket Set: Metric: 1/4" Drive: 2mm, 2.5mm, 3mm, 4mm, 5mm, 5.5mm, 6mm; 3/8" Drive: 7mm, 8mm, 9mm, 10mm, 11mm, 12mm; 1/2" Drive: 14mm, 15mm, 17mm, 19mm. SAE: 1/4" Drive: 5/64", 3/32", 1/8", 5/32", 3/16", 7/32", 1/4"; 3/8" Drive: 9/32", 5/16", 3/8", 7/16", 1/2"; 1/2" Drive: 9/16",5/8", 11/16",3/4". Adapter Set: 1/4"-3/8", 1/4"F-3/8"M, 3/8"F-1/4"M, 3/8"F-1/2"M, 1/4"F-3/8"M The allen hex bit socket set's multiple sizes available for ease of use. High contrast and specific size marking for identification. It helps you select the size easier. It comes with a sturdy and convenient storage case. Keep each piece in the proper position. All products meet or exceed ANSI performance standards.