The Shimano Alfine CS-S500 Sprocket Single-Speed 18T - Silver is a high-quality accessory designed for Alfine 8 and 11 speed hub gears. Made from durable steel, this sprocket is built to last and withstand the rigors of daily use. With 18 teeth and a thickness of 2mm, it provides a smooth and efficient ride, ensuring that your bike performs at its best.