Genuine OEM Volkswagen Engine Coolant Overflow Hose, part number 5Q0121109K. This critical hose is responsible for directing excess coolant from the expansion tank, helping to regulate pressure within the engine cooling system. It is positioned within the engine bay, connecting directly to the coolant overflow reservoir. Weighing 0.07 kg, this hose is designed for durability and resistance to high temperatures and coolant chemicals. A genuine OEM hose ensures correct routing geometry, material flexibility, and resistance to degradation for reliable, leak-free operation.