M-series rear derailleurs are designed to work with 7, 8, and 9-speed Shimano-compatible mountain and road shifters. These Mezzo rear derailleurs are light, robust, and reliable. You can count on them to get any bike on the road. - Weight-saving aluminum bracket body and outer link - Steel pulley cage for extra chain-rub durability - Compatible with Shimano 7, 8, and 9-speed mountain and road systems

M21 rear derailleurs are designed to work with 6- and 7-speed Shimano road and mountain shifters. Enjoy the wide variety of bikes you can get going again with M21 rear derailleurs. - Robust composite and steel construction - Compatible with Shimano 6- and 7-speed mountain and road systems

Not everyone needs the added chain retention of a clutch derailleur. For those riders, we offer a non-clutch version of our innovative ADVENT derailleur. Without the clutch in the system, the shifting effort at the lever is reduced. While still capable of handling an 11-42T cassette, the rear derailleur is the perfect choice for commuter or touring bikes that can benefit from using a wide-range gearing system. - Direct cable routing for smooth and responsive shifting - No clutch for ultra-smooth shifting - Compatible with 11-42T 9-speed cassettes - Compatible with ADVENT shifters only