The Shimano Ultegra RX800 GS 11-speed derailleur is the sister derailleur to the Ultegra R8000 derailleur, but features a "clutch," or what Shimano calls Shadow RD Plus technology. This is designed to reduce chain slap, noise and improve chain retention on bumpy section of riding surface. It is ideally suited to cyclocross, gravel and adventure riding. With it's GS long cage, the derailleur is compatible with up to a 34 tooth cog. The smooth and quick shift performance punches above it's weight class. FEATURES: Pulley maintains consistent distance to cassette for increased shift stability Smooth, compact appearance thanks to Shadow technology Stable shifting performance On/Off switch for integrated clutch SPECS: Maximum Sprocket: 34T Minimum Sprocket: 11T Maximum Front Difference: 16T Total Capacity: 39T Speeds: 11 Weight: 248g