Genuine OEM Audi Coolant Hose, part number 4E0121088N. This hose is a vital component in the engine cooling system, responsible for circulating coolant to regulate engine temperature. It connects various parts of the cooling circuit, as indicated in the assembly diagram. Constructed from durable, heat-resistant rubber and plastic, it measures approximately 0.32 meters in length. Opting for a genuine OEM coolant hose ensures precise fitment, correct fluid flow, and resistance to degradation from heat and coolant chemicals, which is critical for preventing leaks and ensuring the longevity of the cooling system.