The workhorse of X-Range gearing. The SRAM RED XG-1290 cassette progresses fluidly and quickly through a wider range of gears. It's specifically designed for wireless electronic shifting and the one-piece design offers you the best in weight savings.FEATURESDesigned for smooth and fast shiftingGradual gear progression between cogsat least five one-tooth jumpswhile still offering a wider range10-tooth start helps provide a wider gearing rangeDesigned to work with an XDR driver bodyOne-piece machined steel X-DOME design for weight savings