Genuine OEM Volkswagen Clutch Master Cylinder, part number 6R0721405D. This essential component converts the mechanical force from the clutch pedal into hydraulic pressure, which then actuates the clutch slave cylinder for smooth and precise clutch engagement and disengagement. Weighing 0.146 kg and measuring 0.18 meters in length, it is engineered to exact factory specifications. Choosing a genuine OEM clutch master cylinder ensures correct hydraulic pressure, reliable pedal feel, and long-term durability, which are critical for the proper function and longevity of the vehicle's manual transmission system.