The SRAM RED AXS XG-1290 cassette is an integral part of the RED AXS drivetrain system. With a 10-tooth small cog and X-Range gearing, it progresses fluidly and quickly through a wide range of gears. It is designed specifically for wireless electronic shifting, and the one-piece design offers exceptional weight savings. The XG-1290 cassette is designed to operate with XDR driver bodies. FEATURES: More gradual gear progression between cogs (at least five one-tooth jumps) while still offering a wider range One-piece machined steel X-Dome design for weight savings 10-tooth start helps provide a wider gearing range Designed to work with an XDR driver body 12-Speed