S2 steel, the strongest and hardest bits availableSet includes 2 magnetic bit driversBlack storage caseBall torx for limited access areasMaster Ball Drive Bit Set, 32 pc.includes 10-Piece Ball TORX T10 thru T55, 10-Piece Ball Hex Metric 2mm thru 10mm, and 10 -Piece Ball Hex Fractional SAE 3/32 in. thru 3/8". All bits are S2 steel with 1/4 in. hex shanks 1 in. long. magnetic bit holder and magnetic bit driver in black storage case.