TheShimano Deore M6100 12 Speed Cassette 10-51Tuses Hyperglide sprockets that have a computer designed tooth configuration with contoured shift gates, resulting in a crisp smooth shift even under load. Shimano Deore M6100 12 Speed Cassette 10-51T Features 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 For use with 12-speed MTB chains Average weight: 534 g for 10-51T