With its integrated chain stabilizer, the Shimano GRX derailleur ensures quieter shifting and more secure chain management on rough terrain. The RD-RX822-SGS is compatible with Shimano MTB cassettes with 10-51 teeth and 12 speeds, so you'll never run out of gears, even on the steepest jeep roads or the most challenging single trails in the mountains. Additionally, the chain tensioner features an ON/OFF switch that makes removing the wheel easier.