These are Shimano's Flat Mount BR-RX400 hydraulic disc brake caliper with IceTech finned disc pads, and all necessary hardware. The system requires the Shimano SM-BH90-JK-SSR hydraulic hose system from lever to caliper. Shimano's Mineral Oil hydraulic system with ONE WAY BLEEDING makes it fairly simple to set the proper housing length and bleed for best braking contact.

Both calipers are resin dual piston models and are over built for the challenges of the roughest gravel terrain. Each can be set-up for 140mm or 160mm rotor use based on set-up, and the front includes the reversible adapter required for fork installations. A hardware selection is included for most frame and forks, but there can be frame and fork designs that require alternative lengths.