Genuine OEM Volkswagen Expansion Tank Coolant Hose, part number 5N0122447M. This molded rubber hose is designed to connect the coolant expansion tank to the main cooling system, facilitating the flow of coolant and managing system pressure. Its specific shape and material are engineered for durability and resistance to heat and coolant chemicals. Using a genuine OEM hose ensures precise routing, correct pressure handling, and long-term reliability, preventing leaks and maintaining optimal engine cooling.