Genuine OEM Audi Lower Radiator Hose, part number 1K0121051AC. This durable rubber hose is a critical component of the engine cooling system, responsible for transporting cooled coolant from the radiator back to the engine. Its specific molded shape ensures correct routing and a leak-free connection. Using a genuine OEM hose guarantees the correct material composition, pressure resistance, and precise fitment, preventing leaks and ensuring optimal engine temperature regulation.