Genuine OEM Audi Coolant Hose, part number 420121107C. This hose is a critical component of the engine cooling system, designed to convey coolant between various components to maintain optimal engine temperature. It measures approximately 0.61 meters in length and weighs 0.16 kg. Choosing a genuine OEM coolant hose ensures precise fitment, correct routing geometry, and resistance to engine coolants and temperature fluctuations for reliable, leak-free operation.