Genuine OEM Audi Expansion Tank Lower Hose, part number 1K0122109CB. This critical component facilitates the flow of engine coolant, connecting to the lower part of the expansion tank. It ensures proper circulation within the cooling system to maintain optimal engine temperature. Made from durable, heat-resistant rubber, this hose is precisely molded for correct routing and secure connections. Using a genuine OEM hose guarantees exact fitment, resistance to temperature extremes and chemicals, and long-term reliability for the cooling system.