SRAM Red XG-1290 12-Speed CassetteSRAM Red XG 1290 12 Speed Cassette 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. Optimised for Wireless Shifting Designed specifically for electronic drivetrains Smoother, Faster Shifting Refined gear steps with at least five one tooth jumps 10 Tooth