The uninterrupted shifting experience of the Dura-Ace R9200 12-speed cassette range lets you climb, sprint, & push your limits without stopping to think about your next gear change. Larger driving cogs maximize drivetrain efficiency & create compatibility with both Shimano 11 & 12-speed freehub bodies. HYPERGLIDE+ cassettes have revolutionized off-road shifting with their seamless shifts both up & down the gear range. Now it's time for the technology to change road cycling. Even during maximal efforts up a climb or nearing the finish line, riders no longer need to back off to perform a shift. In any gear, Dura-Ace R9250 drivetrains maximize efficiency thanks to larger cogs & retain compatibility with existing 11-speed freehub bodies. All this while increasing to 12-gears & without increasing weight, Dura-Ace CS-R9200 cassettes are the new paradigm in road shifting. Faster, seamless shifts under maximum pedaling load Refined 12 step gear combination provides peak efficiency & accelerating performance for every situation Add wider 34T spec for pro-race usage Compatible with new 12-speed & road 11-speed Freehub body