"Shimano Dura-Ace HYPERGLIDE+ (CS-R9200-12).
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.
 
Available in 11-30t and 11-34t gearing
11-12-13-14-15-16-17-19-21-24-27-30t gears, weight: 223 g
11-12-13-14-15-17-19-21-24-27-30-34t gears, weight: 253 g"
 
- Shimano