The SRAM Force AXS XG-1270 Cassette is optimized for electronic shifting. It features X-Range gearing technology and a 10-tooth small cog to progress fluidly and efficiently. The XG-1270 cassette is designed to operate with XDR driver bodies.-Features at least five one-tooth jumps for a smoother gear progression-Mini cluster construction reduces weight and increases durability-10-tooth start helps provide a wider gearing range-Designed to work with an XDR driver body