Product details:

Shimano Alivio/Sora HG400 9 Speed MTB Cassette Shimano model HG400 Hyperglide sprockets have a computer designed tooth configuration with contoured shift gates, resulting in a crisp smooth shift even under load. Close ratio gearing allows a more efficient use of energy through finer cadence control. Sprockets are cut away and drilled to reduce weight without reducing rigidity. Nickel-plated finish offers hard wearing resistance to corrosion. For super narrow 9-speed HG chains Corrosion-resistant steel cassette lockring.