Durable 7-speed ATB cassette;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 energythrough finer cadence control;Sprockets are cut away to reduce weight without reducing rigidity;Nickel-plated finish offers hard wearing resistance to corrosion, Corrosion-resistant steel cassette lockring. For 7 Speed HG Chains.