Features: Effectively increase chain power inertia, reduce friction, make the chain more stable, and effectively increase the cadence. Using 7075 high-quality aluminum alloy, CNC processing, with high strength, durable and corrosion resistant. S-shaped trajectory can smoothly guide the chain, reduce friction, and save effort in riding. Use the screw kit to fix the guide wheel to ensure that it does not loosen or shake, safer for riding. Carbon fiber frame, aluminum alloy guide wheels processed by CNC cutting, lightweight.