Genuine OEM Audi Alternator Coolant Return Line, part number 079121131AH. This pipe is crucial for managing engine temperature by returning coolant from the alternator to the main cooling system. It ensures the alternator operates within its optimal temperature range, preventing overheating. Constructed from durable metal and rubber, this line is designed for precise fitment and long-term reliability. Choosing a genuine OEM part guarantees the correct material composition and routing geometry, preventing leaks and ensuring efficient coolant flow for critical engine components.