Genuine OEM Audi Coolant Hose, part number 7M3121109AG. This hose is a critical component of the engine cooling system, designed to circulate coolant efficiently. It connects directly to the coolant expansion tank, facilitating the flow of fluid to and from the reservoir. Weighing 0.138 kg and measuring 0.34 meters in length, this hose is engineered for precise fitment and durability. Choosing a genuine OEM coolant hose ensures the correct material composition and routing geometry, preventing leaks and maintaining optimal engine operating temperatures.