R-series rear derailleurs are designed to work with 7, 8 ,9, and 10-speed Shimano-compatible road shifters. These R9 rear derailleurs combine the benefits of R10 and R8 rear derailleurs: compatibility friendly, weight saving, and robust. Features: Weight saving aluminum bracket body and outer link Steel pulley cage for extra chain-rub durability Compatible with Shimano 7, 8, 9, and 10-speed road systems Not compatible with Shimano Tiagra 4700 road system Medium cage for double 34T setup Specs: Rear Derailleur Mount Type10x1 Standard Cage LengthMedium ColorBlack Rear Der/Shifter CompatibilityShimano Road