The new Dura Ace from Shimano is the answer to the question of many professionals and ambitious amateurs alike, if and how the current, already immensely high level of performance could be increased even further. Every single Dura Ace R9100 component is designed to work together with all the other components of the system with maximum efficiency. This is where the core of Shimano's philosophy of components designed as a system becomes particularly clear. The result is called SYSTEM SUPREMACY - the superiority of the system over the sum of its parts. Shimano's High End Racing Wheel Set includes sealed precision bearings on both wheels, which ensure easy and low-friction drive operation. - Type: Rear derailleur rollers - Scope of delivery: 1 Shimano Dura Ace rear derailleur roller set (1 tension roller, 1 guide roller) - Suitability: Rear derailleur - Compatible with: Shimano Dura Ace RD-R9100 / Dura Ace Di2 RD-R9150