Shimano GRX RD-RX820 Rear Derailleur 12 SpeedThe Shimano GRX RD-RX820 Rear Derailleur 12 Speed is compatible with 11-34t and 11-36t 12-speed cassettes, providing a wide gear range so you can spin a comfortable cadence no matter the terrain type. This rear derailleur also features an integrated chain stabilizer that delivers quieter shifting and more secure chain management during rough rides. The chain tensioner has an ON/OFF switch for outings on smooth surfaces. Compatible with HG 12 Speed Chains. Weighs 270g. Comes in one cage length.192790303611
