Grab ahold of Shimano's Dura-Ace Di2 Front Derailleur and say hello to near-telepathic shifting. This futuristic front derailleur monitors the position of both derailleurs and trims automatically, ensuring that you have proper derailleur position and no chain rub, no matter what chainring and cog combination you may find yourself in. This is also the fastest and most accurately shifting front derailleur Shimano has ever made, getting you into the big ring more reliably and with greater speed. The derailleur uses Shimano's E-Tube wiring system for waterproof connections and simple, clean setup, and the lack of cables and housing increases service life and reliability.
Capacity is calculated by subtracting your smallest chainring's tooth count from the largest chainring's tooth count. Example: 46/34/24 chainrings: 46 - 24 = 22-tooth capacity.