Genuine OEM Audi Coolant Hose, part number 427121109B. This hose is a vital component of the engine's cooling system, responsible for transporting coolant. It is located in the engine bay, connecting to the water pump and other cooling system parts. Made from robust, heat-resistant rubber to withstand demanding operating conditions. Genuine OEM coolant hoses are engineered for precise fitment and optimal coolant flow, ensuring efficient engine temperature regulation.