Genuine OEM Audi Radiator Lower Coolant Hose, part number 4F0121055F. This hose is responsible for returning cooled coolant from the radiator to the engine, completing the cooling circuit. Made from durable rubber, it is designed to withstand continuous exposure to coolant and temperature fluctuations. Weighing 0.3195 kg, genuine OEM hoses ensure correct routing geometry, material composition, and resistance to coolant chemicals, preventing leaks and maintaining optimal engine temperature.