1. Material: crank is made of high quality aluminium alloy material, to use.Crank length 170MM. Crank screw diameter 15MM. Good quality not only can provide a r guarantee for your life, but also good materials can increase product life. 2. Material: crank is made of high quality aluminium alloy material, to use.Crank length 170MM. Crank screw diameter 15MM. Good quality not only can provide a r guarantee for your life, but also good materials can increase product life. 3. Material: crank is made of high quality aluminium alloy material, to use.Crank length 170MM. Crank screw diameter 15MM. Good quality not only can provide a r guarantee for your life, but also good materials can increase product life. 4.Feature: and compact appearance, crank arm set can make your car more attractive. The BCD of this Crankset is 104mm, inside BCD 64mm. 5.Excellent Performance: crank has stable performance, high reliability. Exquisite workmanship, stylish and generous appearance. You can buy it with confidence. Product quality is worthy of your trust. 6.Brilliant Compatibility: Conform to strict quality control standards, dependable to use. Crank arms is a good accessory for remodeling mountain bike. The crankset has strong axial strength and strong compatibility. Compatible: single, double, and triple speed. 7.After-s Guarantee: If you have any questions about the product,or you encounter problems with your use, you can us directly.We will provide you with a solution in good time. No need worry about after- s. 8. Material: crank is made of high quality aluminium alloy material, to use.Crank length 170MM. Crank screw diameter 15MM. Good quality not only can provide a r guarantee for your life, but also good materials can increase product life. 9. Material: crank is made of high quality aluminium alloy material, to use.Crank length 170MM. Crank screw diameter 15MM. Good quality not only can provide a r guarantee for your life, but also good materials can increase product life.