12 pc. 3/8" Dr. Fractional Set Designed for professional tool users. Engineered specifically for use with impact tools, using the most up to date industrial specifications. Made from high quality alloy steel (chrome-molybdenum). Thorough and exact heat treatment ensures the correct balance of stength and duability. Tested to the highest specifications to deliver outstanding performance at the most competitive cost. Increased Strengh - Transfers the pressure from the thinnest part of the socket wall toward the thicker section, resulting in increased strength. Increased Torque - Allows up to 20% more torque to be applied than on standard impact sockets. Easier Access to Tight Areas - The shift in pressure allows us to reduce the socket wall thickness, increasing access to tight areas Set Includes: 3/8 Drive Standard Length Sockets: 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8, 15/16, 1, and Molded Storage Case 1213