Description:Naturally, our product is light in weight, which it is easy to carry and install. And it also will not easy to slide and deform because it has uniform force.Surely, the long service life is due to the use of anodized technology. At the same time, it is not easy to fade and oxidate because of the use of coating coloring technology. And it also has high hardness.It is made from aluminum alloy, is durable to use.There are two sizes of the product to choose from.With strong compatibility, suitable for most bicycles on the market.Item Name: Bicycle Crank BoltsMaterial: Aluminum AlloyFeatures: Fit Seamlessly, Anti-rust, Rigidity Specification: 12(M12), 15(M15)Reminder: Spline center shaft crank set screw, pay attention to the choice of size, use 8MM hexagonal wrench for disassembly and assembly.Size Details: 12 Size: 2.05cm x 2.04cm x 2.04cm/0.81" x 0.8" x 0.8" (Approx.)15 Size: 2.12cm x 2.03cm x 2.03cm/0.83" x 0.8" x 0.8" (Approx.)Notes:Due to the light and screen setting difference, the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Bicycle Crank Bolts