Engineered for smooth, reliable gear shifting on gravel, broken roads and rides that mix up the terrain, the GRX 812 11-Speed Rear Derailleur brings the quality of proven Shimano mechanical performance to your adventure exploits. The adjustable stabiliser uses spring force and friction to maintain high chain tension so that over bumpy or unpredictable surfaces chain slap, drivetrain noise and the chance of the chain dropping are reduced. The result? A smoother, faster ride. A useful upgrade to your road setup, this derailleur is compatible with current Dual Control Levers and has a total capacity of 31T.