Genuine OEM Volkswagen Coolant Hose, part number 2HJ122073J. This hose manages coolant circulation for both engine cooling and cabin heating functions. It is identified as part 31 in the diagram, indicating its specific location within the cooling system assembly. Made from robust materials, it is engineered to handle the demands of coolant flow under various temperature and pressure conditions. Genuine OEM coolant hoses are essential for maintaining the integrity of the cooling system and ensuring optimal performance.