Shimano broke the mold with their Dura-Ace Di2 group. Effortless shifting, instant engagement, unparalleled performance. Well, now you can get electronic shifting without shelling out all that dough. The Ultegra Di2 group is a more affordable version of the Dura-Ace Di2 group, so you can enjoy many of the benefits, without the high price tag. This rear derailleur is also equipped with a built-in safety function and recalibration function in the event of impact, which keep your drivetrain working just it was the day it left the bike shop.
Item No. » SH-RD6770
SAVE 37% = $125.001 or more: $214.99