Optimised spring return - On rough roads, the spring positioned between the upper body and the pivot absorbs the vibrations, ensuring the chain always rest properly on the sprockets12-tooth jockey wheel on the rocker arm, perfect for use with cassettes that have a wide range of teeth and ensures constant chain tensionRemovable pivot is compatible with hanger mount and direct mount style framesCompatible with spacing and axle types commonly associated with new hydraulic road disc brake applicationsLonger cage for 11-34t cassette compatibilityRD20-SR12412sp34LongBLK200gUPC/EAN/GTIN: 8053340455490