High quality S2 steel bits with a zinc phosphate finish, each size in 30 and 75mm lengths. Hardened (58-62 HRC) and tempered for added strength. Contents: TRX-Star Bits; T20, T25, T30, T40, T45, T50, T55, T60 (1 each 30 and 75mm), Hex Bits; 4, 5, 6, 7, 8, 10, 12mm (1 each 30 and 75mm), Spline Bits; M5, M6, M8, M10, M12 (1 each 30 and 75mm), Drive Adaptors; 3/8"Sq x 10mm Hex, 1/2"Sq x 10mm Hex.