GRX ST-RX715 Di2 Shift/Brake Lever with BR-RX410 Disc Brake Caliper - Shimano
And despite its compact construction, the system is quieter and easier to maintain. Shimano GRX ST-RX715 Di2 Shift/Brake Lever with BR-RX410 Hyd Disc Brake Caliper - Right/Rear, 12-Speed, Flat Mount.