Super lightweight 12speed hg cassette with a rigid carbon and alloy carrier for excellent shifting even under the most demanding gear changes'. '.strtoupper('h')yperglide sprockets have a computer designed tooth configuration with contoured shift gates resulting in a crisp smooth shift even under load'. '.strtoupper('c')lose ratio gearing allows a more efficient use of energy through finer cadence control largest sprockets are mounted on lightweight alloy and carbon carriers to reduce weight and increase rigidity 5 largest sprockets are made from titanium to reduce weight without sacrificing strength sprockets are extensively cut away and drilled to further reduce weight without reducing rigidity nickel plated finish offers hard wearing resistance to corrosion alloy cassette lockring for super narrow 12 speed chains