Shimano Ultegra CS-R8101 12-Speed Cassette Size:11-34T but don't let its understated

but don't let its understated disposition fool you - Level gives you the art of braking in minimalist form

Medium/Large fit

After two years of development and testing the MK5 Penthouse Flat is here

Compatible with HG 12-speed chain

NX Look for boost logo or 3mm offset on inside of chainring Direct Mount

Shimano Ultegra CS-R8101 12-Speed Cassette Size:11-34T but don't let its understatedNew tooth profile designed to work with both electronic and mechanical Shimano drivetrains. Tooth profile slightly changed to better accomodate mechanical shifting For Di2 and Mechanical Shifting Systems Refined 12 step gear combination provides peak efficiency and accelerating performance for every racing situation Faster, smoother shifts under maximum pedaling force Compatible with new 12 speed (HG Spline L2) and road 11 speed (HG 11) freehub bodies