Genuine OEM Audi Coolant Hose with Coupling, part number 5N0122101BH. This hose is a critical component in the engine cooling system, designed to connect various parts and facilitate the flow of coolant. It ensures efficient heat transfer and maintains optimal engine operating temperatures. Choosing a genuine OEM coolant hose guarantees the correct material composition and routing geometry, preventing leaks and ensuring long-term reliability under thermal and pressure stresses.