Improve your road bike's performance with this 11-speed cassette from AirBike. Made with a durable aluminum alloy and steel bracket, this cassette fits Shimano, Sram, and Sunrace replacement freehub/driver types. With 11-28 teeth and 11 speeds, this cassette is compatible with Altus, Alivio, and Acera models. The largest sprocket is 28 tooth, while the smallest is 11.