ST-RX400L/BR-RX400R 1700mm Left rear ST-RX400-L Shimano GRX - Hydraulic disc brake - Dual control lever - 2x10 speed Improved controllability for various terrains Lever shape and bracket ergonomics suitable for gravel riding Sliding Difficult brake lever shape Light shifting operation similar to higher grade road systems BR-RX400-R Shimano GRX - Flat mount - Hydraulic disc brakes - Brake calipers No hesitation on rough roads Excellent heat dissipation Ice technology Flat mount Designed for ease of assembly and maintenance Excellent tool access Easy hose joint system (J-Kit) Simple wheel replacement Clean Bleeding system One-way bleeding JKIT has each part filled with oil and a hose connected to the caliper side, greatly increasing assembly efficiency. It is now possible to significantly reduce the time for bleeding and air removal!