1.Premium material: this crankshaft cap is made of aluminium alloy, is high strength, corrosion resistant, robust and durable. With antirust, colorfast, lightweight and durable. Good treatment with fine texture, ensure long life. 2.Easy to install: these bicycle crank screws are lightweight, easy to install and use. Fits most mountain bikes with hollow axle. It is used for bicycle integrated hollow cranksets. It is used to fix the crankset and the chainring crank. 3.Great decoration: the mountain bike crank screw has more different colours to choose from, meeting different needs. The bright color makes it a great decoration for your bikes. 4.Distributes pressure: this crankshaft cap can distribute the pressure of the nut to the part to be secured and thus reduce the risk of damage to the part. The fine design with precise machining fits perfectly with the crank and provides professional crank fixation.