Genuine OEM Audi Rear Breather Line, part number 4G0201991H. This line is essential for allowing the ventilation of gases within the fuel system, preventing pressure buildup and ensuring proper fuel tank operation. It is positioned on the left rear side of the fuel tank assembly. Weighing approximately 0.043 kg and measuring 0.56 m in length, this line is constructed from durable, fuel-resistant material. Using a genuine OEM breather line ensures precise fitment, leak-free operation, and compliance with emission standards, critical for both safety and environmental performance.