Genuine OEM Audi Coolant Line, part number 5Q0121064CN. This flexible, corrugated hose is an integral part of the engine cooling system, responsible for transporting coolant between various components such as the radiator, engine block, and other heat exchangers. It ensures efficient heat dissipation and maintains the engine at its optimal operating temperature. This coolant line measures approximately 0.59 meters in length and weighs 0.2 kg. Using a genuine OEM coolant line guarantees the correct material composition, resistance to high temperatures and pressures, and precise routing geometry, which are essential for preventing leaks and ensuring the long-term reliability of the engine cooling system.