Genuine OEM Volkswagen Coolant Hose, part number 3Q0122157K. This hose is a vital component of the engine cooling system, responsible for circulating coolant between various engine components, such as the radiator, engine block, and heater core. It is designed to withstand high temperatures and pressures. Using a genuine OEM coolant hose ensures the correct material composition, precise routing geometry, and durable connections for a leak-free and efficient cooling system, preventing engine overheating.