Genuine OEM Volkswagen Coolant Hose, part number 7T0122051M. This hose transports coolant between engine components and the radiator, featuring a quick-release coupling for easy installation, and is designed for vehicles with auxiliary heating systems. It is located at position 1 in the diagram. Genuine OEM coolant hoses are manufactured to precise specifications to ensure correct flow rates and durability under extreme temperatures and pressures.