MaterialThe bottom bracket is made of durable, high-strength, rust-proof, corrosion-resistant steel, and has a hardened and heat-treated square hole spline bushing, which can be used with a socket, wrench or spanner wheel of 24 mm. [Portable] The ATV centerline tool is small and portable, with a single weight of 112g and a single size of 5*2.9*2.9cm. High PerformanceThe bicycle hub tool is specially designed for removing and installing DT and hub pawls. Necessary GadgetBike Crank Remover is a must-have gadget for repairing your bike and can be in the toolbox of any bike you own. [Note] Special attention should be paid to the center shaft of the spline. Not used if center shaft length exceeds 118mm. Since the diameter of the splined center shaft is relatively large, it will be blocked by the pitch of the socket tool. Any size over 130mm will work if the square hole is good.