ATD Tools 13782 10-Piece Triple Square Spline Bit Socket Set (10) Triple Square Spline Bit Sockets: M4 1/4" Drive (ATD-232); M5 1/4" Drive (ATD-233); M6 1/4" Drive (ATD-234); M8 3/8" Drive (ATD-235); M9 3/8" Drive (ATD-236); M10 3/8" Drive (ATD-237); M12 3/8" Drive (ATD-238) M14 3/8" Drive Tamperproof (ATD-239); M16 1/2" Drive Tamperproof (ATD-241); M18 1/2" Drive Tamperproof (ATD-242) Includes triple square spline bit sockets Bits are made from S2 steel to meet or exceed torque specifications Sockets are made from heat treated chrome vanadium steel for strength and durability