The 11-speed DURA-ACE Di2 derailleur ensures ergonomic, stable, and effective shifting thanks to its low-profile design and SHIMANO Shadow RD. Due to its clever design, it accommodates cassettes with a range of 11–30. Synchronized Shift allows for more efficient gear changes while riding. This feature offers numerous benefits, such as faster, more precise shifting under all riding conditions and minimizes stress on the drivetrain. When Synchronized Shift is activated, both the derailleur and front derailleur can be controlled with a single switch. With fully activated Synchronized Shift functionality, the front derailleur detects the position of the rear derailleur and automatically shifts to the most efficient gear with the best chain line, so you no longer have to worry about front shifting or trim adjustments. With the Semi-Synchronized Shift function activated, you can manually shift the front derailleur, giving you optimal control for selecting the best gear combination for your riding style. The system automatically makes the necessary correction by shifting to the correct rear gear with the best chain line.