Genuine OEM Volkswagen Crankcase Vent Valve, part number 028129101D. This valve is a key component of the positive crankcase ventilation (PCV) system, regulating pressure and removing harmful blow-by gases from the engine's crankcase. It helps prevent oil leaks and maintains engine cleanliness. Typically integrated into the engine's intake or valve cover system. Constructed from durable plastic, it weighs approximately 0.074 kg. A genuine OEM valve ensures proper pressure regulation and prevents engine damage, crucial for long-term engine reliability.