Shimano GRX offers gravel-specific ergonomics, optimized gearing, and rugged reliability for a quiet and stable drivetrain. The GRX hydraulic disc brake 12-speed Di2 STI levers provide excellent control, modulation, and power with minimal effort in all riding conditions. Features include a higher brake lever axis and curved lever for improved grip and confidence on rough surfaces and descents, and a raised hood head to prevent hand misalignment and slippage. The recessed finger notch stops upward hand slipping during braking, and anti-slip texture and brake lever coating enhance braking efficiency and reduce fatigue on long rides. This 12-speed E-tube Di2 compatible kit contains a bled left hand ST-RX825 STI, a BR-RX820 flat mount rear brake caliper with pads, hose, and mineral oil (without rotor or adapter).