Newest Shimano cassette in the Dura Ace series, which is the top model within cassettes from Shimano.

The cassette is made for Shimano's new Spline system, which creates a larger contact surface between the cassette and cassette casing for better power transfer. They have therefore been developed for the new Spline, but can also be used on 11-speed HG cassette cases.

Unlike the 11 speed cassettes from Shimano, you get a more even exchange on the gears, and especially the gears that Shimano calls the "sweetspot gears" have less jump between each other. In addition, the profile of the teeth is different than before, which ensures more consistent gear changes even under high loads.

The cassette is super light with a weight of only 253 grams.