Precision Braking: SHIMANO GRX BR-RX400 hydraulic disc brake system delivers exceptional stopping power and modulation for enhanced control and safety Versatile Mounting: Flat mount design with adapter compatibility for both 140mm and 160mm rotors provides flexible installation options Advanced Pad Design: L03A resin pads with cooling fins optimize heat dissipation and maintain consistent braking performance during extended use Superior Control: Hydraulic system ensures smooth and responsive brake actuation with minimal effort required at the lever Performance Design: Purpose-built for gravel and adventure riding, offering reliable braking performance across various terrain conditions