Genuine OEM Audi Brake Master Cylinder, part number 4H0611021. This essential component is responsible for converting pedal force into hydraulic pressure, distributing it to the brake calipers and wheel cylinders. It is a central part of the vehicle's hydraulic braking system. Constructed from durable materials, it weighs approximately 0.75 kg. Opting for a genuine OEM brake master cylinder ensures precise hydraulic control, optimal braking performance, and long-term reliability for critical safety.