SRAM Red22 11-Speed Short Cage Rear Derailleur Extended B-Knuckle for improved clearance for 28t cassettes Exact Actuation shifting provides fast, accurate shifts Carbon Cage designed for precise chain management and new reduced profile carbon inner cage Aeroglide Pulleys with High Grade Black Box Hybrid Ceramic Bearings that reduce drive train drag and lower drive train running noise Weight: 145gm (short cage)