This tool contains a variety of hex wrench sizes which fit most regulator fittings. Each Mini Tool also includes Phillips head and flat head screw drivers. All models include 2mm, 2.5mm, 3mm, 4mm, 5mm and 6mm hex wrenches. TM0328 and TM0346 models include 8mm hex wrenches. All wrenches are made of Chrome-Vanadium steel!