Genuine OEM Audi Water Coolant Hose, part number 5N0121101K. This hose conveys water and coolant for engine temperature regulation, playing a vital role in preventing engine overheating. Weighing 0.107 kg and measuring 0.23 m in length, it is constructed from durable rubber. Using a genuine OEM hose ensures the correct material composition and precise shape for optimal flow and resistance to thermal cycling and pressure, preventing leaks and maintaining cooling system integrity.