ST-RX400 GRX mechanical shift hydraulic STI leverShimano 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 GRX hydraulic disc brake STI's give you control, modulation and power with minimal effort in all riding conditions Raised hood head prevents hand misalignment and slippage Anti slip texture and brake lever coating gives higher braking efficiency and reduces fatigue on