Genuine OEM Audi Lower Engine Coolant Hose, part number 4E0121101AC. This hose is an essential component of the engine cooling system, responsible for transporting coolant to maintain optimal engine operating temperatures. It is positioned as a lower connection within the cooling circuit. Made from durable rubber and plastic, it measures approximately 0.33 meters in length. Choosing a genuine OEM hose guarantees exact routing, proper sealing, and resistance to thermal and pressure stresses, crucial for preventing leaks and ensuring long-term cooling system reliability.