Genuine OEM Volkswagen Coolant Hose, part number 3C0121086M. This hose is designed to transport coolant between the engine and radiator, playing a crucial role in regulating engine temperature. It is located at position 21 in the cooling system diagram. Constructed from durable rubber, it ensures reliable fluid transfer and temperature management. Genuine OEM hoses are manufactured to precise specifications, guaranteeing correct fitment and resistance to heat and pressure, which is vital for preventing leaks and ensuring the longevity of the cooling system.