Sunrace CSR91 9 Speed Cassette 11-25T NickelThe Sunrace CSR91 9 Speed Cassette is an excellent cassette to replace your damaged or worn out 11-25T road cassette. The Super Fluid Drive Technology enables your shifting to be smooth, consistent, and quiet. The lock ring is aluminum but the cogs are steel. Weighs only 280g. This is equivalent to the Shimano CS-HG50 9-speed cassette.4710944242133