Prestacycle Bicycle Tool Bits Professional Tools Not all tools are made the same. Different grades of steel are stronger and more durable than others. The Prestacycle Bicycle Tool Bits are compatible with all Prestacycle hex-based hand tools, and are industry-standard to fit all other tools that use 1/4" hex bits. All Prestacycle Professional bits are made with hardened S2 steel, which is much stronger than most hand tools made of CRV Steel. S2 steel also resists stretching, preventing rounded edges on the bits that could damage bolts. Prestacycle applied nickel-plating to all Professional bits to prevent marring to stainless steel, aluminum, and titanium screws and to provide a long-lasting finish. Features The kit includes: 2/3/4/5/6/8mm hex, T8/T10/T15/T20/T25/T27/T30 Torx, Philips 1/2, and 1/8" and 3/16"Flat Bits made of hardened S2 steel Industry standard sizing to fit all other tools that use 1/4" hex bits | Prestacycle | Bicycle Tool Bits 18 Piece