Genuine OEM Volkswagen Clutch Master Cylinder, part number 6R0721405E. This critical component converts the mechanical force from the clutch pedal into hydraulic pressure, actuating the clutch release mechanism. It is an integral part of the clutch hydraulic system. Weighing approximately 0.145 kg, this master cylinder ensures precise and consistent clutch operation. Choosing a genuine OEM master cylinder guarantees correct hydraulic pressure, fluid compatibility, and long-term reliability for smooth gear changes.