Genuine OEM Audi Water Coolant Supply Hose, part number 4KE819928H. This hose is responsible for supplying coolant to various engine components, playing a critical role in the engine's thermal management system. It is positioned within the engine cooling circuit. Constructed from durable, heat-resistant rubber with a protective braided sleeve, it ensures reliable coolant flow. Using a genuine OEM hose guarantees correct routing, precise fitment, and resistance to coolant chemicals, preventing leaks and system failures.