Titan 3/8 inch Drive SAE Spline Set - 8 Piece includes 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16 and 3/4 inch sockets on a handy socket rail. It has chrome vanadium steel construction. It has precise radial spline teeth that engage the fastener over a wider area to minimize stress. It allow use of higher torque without damage to the fastener or the tool. It also fits a variety of other fasteners: 12 point (triple square), torx, 6 point, square and damaged fasteners.