Genuine OEM Audi Coolant Reservoir Tank Hose, part number 8K0121081BH. This hose transports coolant between the reservoir and the main cooling system, maintaining proper fluid circulation. It is located within the engine cooling system. Weighing 0.55 kg, this hose is made from durable, heat-resistant rubber. Choosing a genuine OEM hose ensures the correct routing geometry, material resistance to coolant, and proper sealing for a leak-free and efficient cooling system.