Shimano CS-M6100 Deore 12-Speed Cassette, 10-51tShimano CS M6100 Deore 12 Speed Cassette, 10 51t Deore M6100 12 Speed Micro Spline MTB cassette featuring light weight minimal design sprocket carrier. Features: 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