I changed the rear derailleur of my groupset because I could no longer link it to my shifters. The repair technician told me this was because my shifters were too old and the system was no longer compatible. After struggling with it, I decided to change my entire groupset. The parts I am selling are functional. The front derailleur worked very well but drains the batteries quite quickly (~1 week). I am open to answering any questions, thank you.