FD-R7150Shimano Di2 electronic shifting lets you change from the big to small chainrings, or vice versa, whenever you like while minimizing the risk of a dropped chain. Similarly, you can perform rear shifts without the need to trim the front derailleur to avoid chain rub. Full and semi synchronized shifting functions can be selected using the E Tube app. With digitally accurate electronic shifts and coordinated communication between shifters and derailleurs,