Genuine OEM Audi Crankcase Housing Non-Return Valve, part number 059103176B. This valve is crucial for regulating pressure within the crankcase housing, preventing excessive pressure buildup or vacuum that could lead to engine damage or oil leaks. It sits within the crankcase assembly. Weighing only 0.016 kg, this compact valve is precisely engineered. Using a genuine OEM valve ensures correct pressure calibration and material integrity, vital for long-term engine reliability and performance.