High performance 11-speed Dyna-Sys II 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 lightweight alloy carriers to reduce weight & increase rigidity Sprockets are cut away & drilled to further reduce weight without reducing rigidity Light & durable 40/42T sprockets Chrome-plated finish offers hard wearing resistance to corrosion Alloy cassette lockring For 11-speed HG-X11 MTB chains