Shimano GRX, with its gravel specific ergonomics, optimized gearing options, rugged reliability, and quiet and stable drivetrain, sets itself apart from the rest of the component world. Low profile Shadow Plus design 12-speed rear derailleur for fast and precise shifting performance. Shadow Plus uses a chain stabilising switch that when on will reduce chain bounce in rough terrain maintaining more stable drive and shifting. High tolerance cold forged aluminium link plates and body construction is extremely light and durable. Compatible with 12-speed Hyperglide+ chains. Wide gear ratio compatible up to 10-45T. For use with single chainset.