Shimano ACERA CS-HG41 8 Speed Cassette The Shimano Acera CS-HG41 8-speed cassette has a computer designed tooth configuration with contoured shift gates, combined with close ratio gearing which allows a more efficient use of energy through finer cadence control, the result is a very crisp, smooth shifter even when under load. Finer cut to reduce weight without compromising rigidity whilst nickel-plate finished offers hard wearing resistance to corrosion. Features: Smoother shifts even under load. Close ratio gearing for finer cadence control. Hard wearing and resistant to corrosion.