With an integrated chain stabilizer mechanism, the SHIMANO GRX 11 speed derailleur provides a quieter experience and shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features and ON/OFF switch for the chain tensioner. The RD-RX812 rear derailleur is compatible with mtb cassettes with a 42T low sprocket max.FEATURE: Adjustable chain stabilizer prevents chain slapping and drops Switch stabilizer ON/OFF to match the terrain Gravel-tuned clutch tensionBENEFIT: Silent and uninterrupted rear shifting on rough terrain Smooth and reliable mixed surface shifting Compatible with current road DUAL CONTROL LEVER Top sprocket: Max. 11T/Min. 11T Low sprocket: Max. 42T/Min. 40T Total capacity: 31T
