Genuine OEM Volkswagen Engine Coolant Overflow Hose, part number 1KM122109C. This critical hose safely routes excess coolant from the radiator or engine to the overflow reservoir, helping to regulate system pressure and prevent coolant loss. Made from durable rubber, it is designed to withstand engine temperatures and coolant chemicals. Choosing a genuine OEM hose ensures correct routing geometry, proper fluid resistance, and reliable sealing, preventing leaks and maintaining cooling system integrity.