Mounting a crank becomes easy with this handy crank bolt mounting key. Both the serrated Shimano crank bolt and the hexagonal Sram and Raceface crank bolts are easily loosened and tightened with this handy tool. The wide wings offer grip and hold. This allows you to put more power on it so that even rusted bolts come off. If even that does not work, there is also the possibility of creating a larger lever through the socket recess.