Designed for smooth and fast shifting and progresses fluidly and quickly through a wider range of gearsGradual gear progression between cogs - at least five one-tooth jumps - while still offering a wider range10-tooth start helps provide a wider gearing rangeOne-piece machined steel X-DOME design for weight savingsDesigned to work with an XDR driver body10-28t12s10,11,12,13,14,15,16,17,19,21,24,28RainbowXG-1290UPC/EAN/GTIN: 710845886140