Experience the uninterrupted precision of the ULTEGRA CS-R8101 12-speed cassette range, engineered to empower your climbs, sprints, and cruises without interruption. With larger driving cogs optimizing drivetrain efficiency, these cassettes seamlessly integrate with both Shimano 11 and 12-speed FREEHUB bodies, ensuring versatility and compatibility. Embracing the legacy of HYPERGLIDE+ technology, renowned for its off-road prowess, the ULTEGRA R8150 drivetrain elevates road cycling shifting to new heights. Say goodbye to compromises during maximal efforts, as seamless gear shifts keep you in the zone whether ascending a climb or outpacing a friend. Retaining compatibility with existing HYPERGLIDE FREEHUB bodies while advancing to 12 gears, ULTEGRA CS-R8101 cassettes define the pinnacle of road cycling shifting performance. The Ultegra CS-R8101 is the upgraded replacement of the CS-R8100 12-Speed Cassette, refined to work seamlessly with both Shimano Di2 and Mechanical 12-Speed Drivetrains.