High quality Chrome Vanadium S2 steel bits. Hardened (58-62 HRC) & tempered for added strength. TRX-Star* Bits; T20, T25, T30, T40, T45, T50, T55, T60 (1 each 30 & 75mm), Hex Bits; 4, 5, 6, 7, 8, 10, 12mm (1 each 30 & 75mm), Spline Bits; M5, M6, M8, M10, M12 (1 each 30 & 75mm), Drive Adaptors; 3/8" Sq x 10mm Hex, 1/2" Sq x 10mm Hex. Supplied in carry-case with inclined tray for quick & easy bit selection. Model No. AK21942