Genuine OEM Audi Engine Coolant Hose, part number 4K0121447AE. This hose is a vital component of the engine cooling system, responsible for transporting coolant between various engine components and the radiator to maintain optimal operating temperatures. It is positioned within the cooling circuit, often connecting heat exchangers or engine blocks. Made from durable, heat-resistant reinforced rubber, it measures approximately 150mm long. Using a genuine OEM coolant hose ensures the correct routing geometry, material integrity, and resistance to high temperatures and pressures, preventing leaks and engine overheating.