SRAM Red22 11-Speed Short Cage Rear Derailleur;

If you want for the fastest, quietest shifting 11 speed around, look no further. The SRAM Red22 Rear Derailleur has been designed to deliver the performance advantage you've come to expect from SRAM. The derailleur is built upon SRAM's Exact Actuation technology for precise, efficient shifting. They have paid close attention to the finer details, like adding a hollow titanium anchor bolt and even refining tooth geometry of the jockey wheel. The result is that the chain runs through the new Red Rear Derailleur smoother and quieter than ever before.