Genuine OEM Audi Coolant Hose With Valve, part number 4L0121081B. This component controls the flow of coolant within the engine cooling system, ensuring proper temperature regulation and efficient heat exchange. It is an integral part of the cooling circuit. Weighing approximately 0.22 kg, this hose is manufactured to exact specifications. Choosing a genuine OEM coolant hose ensures correct routing geometry, material composition, and resistance to temperature and pressure fluctuations, preventing leaks and maintaining system integrity.