Shimano CS-R7100 105 12-speed CassetteHigh performance Hyperglide+ 12 speed 105 Road 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 energy through finer cadence control Largest sprockets are mounted on a lightweight alloy carrier to reduce weight and increase rigidity Sprockets are cut away and drilled to further reduce weight