The uninterrupted shifting experience of the Dura-Ace R9200 12-speed cassette range lets you climb, sprint, and push your limits without stopping to think about your next gear change. Larger driving cogs maximize drivetrain efficiency and create compatibility with both Shimano 11 and 12-speed freehub bodies. Hyperglide+ cassettes have revolutionized off-road shifting with their seamless shifts both up and 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 and retain compatibility with existing 11-speed freehub bodies. All this while increasing to 12-gears and without increasing weight, Dura-Ace CS-R9200 cassettes are the new paradigm in road shifting. Features Faster, seamless shifts under maximum pedaling load. Refined 12 step gear combination provides peak efficiency and accelerating performance for every situation. Add wider 34T spec for pro-race usage. Compatible with new 12-speed and road 11-speed freehub body.