Genuine OEM Audi Crankcase Ventilation Hose, part number 057103227AF. This hose is a crucial part of the engine's crankcase ventilation system, designed to manage and recirculate blow-by gases, preventing pressure buildup and maintaining engine cleanliness. It connects to the engine block, typically near the cylinder head or valve cover, as part of the PCV (Positive Crankcase Ventilation) system. Constructed from oil and heat-resistant materials, it weighs approximately 0.20 kg and measures 0.45 meters in length. Using a genuine OEM ventilation hose ensures proper routing, precise fitment, and resistance to oil and heat degradation, which is vital for maintaining engine health and emissions compliance.