Genuine OEM Volkswagen Coolant Hose, part number 2HJ122073G. This hose directs coolant flow to the heater core to provide cabin heating. It is positioned as part 3 in the diagram, connecting components within the engine cooling system. The hose is constructed from durable rubber material designed to withstand engine temperatures and pressures. Genuine OEM coolant hoses are manufactured to exact specifications, ensuring proper flow and preventing leaks for reliable cabin heating and engine temperature management.