Genuine OEM Audi Coolant Hose, part number 4G0121447AL. This hose is a vital part of the engine cooling system, responsible for transporting coolant between various engine components to maintain optimal operating temperatures. It measures approximately 16 cm long. Choosing a genuine OEM coolant hose ensures the correct material composition for heat and pressure resistance, along with precise routing and connection points, which is critical for preventing leaks and maintaining the efficiency of the cooling system.