The Shimano Ultegra R8150 Di2 12 Speed Rear Derailleur is engineered to ensure fast and smooth 12-Speed gear shifting for competitive racing and demanding conditions.
Fastest ever rear shifting, 58% faster than RD-R9150
Compact design includes an integrated wireless unit, charger, and switch
LED status indicator
Adjust mode, etc.
Wider range capacity
Max. low sprocket: 34T
Rear Derailleur: Shimano Ultegra Di2
Speed: 12 Speed
Time Trial: Yes