SRAM Cassette XG-1270 D1 12 Speed
SRAM Cassette XG-1270 D1 12 Speed, Features at least five one-tooth jumps for a smoother gear progression10-tooth start helps provide a wider gearing rangeDesigned to work with an XDR(TM) driver bodyMINI CLUSTER(TM) construction reduces weight and increases durabilityAll Zipp wheels starting from 2012 are XDR(TM) ready