12-speed shifter with brake lever for use with GRX RX610 12-speed systems. Shimano GRX ST-RX610 Shift/Brake Lever with BR-RX400 Hyd Disc Brake Caliper - Right/Rear, 12-Spd, Flat Mnt Caliper, For. GRX BR-RX400 flat mount 2-piston brake caliper provides excellent heat dissipation with the help of Shimano's ICE technologies.
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