Genuine OEM Audi Coolant Hose with Coupling, part number 3D0122051S. This essential component is responsible for transporting coolant throughout the engine cooling system, maintaining optimal operating temperatures and preventing overheating. It features an integrated coupling for a secure connection within the cooling circuit, as shown connecting to the radiator in the diagram. Weighing approximately 0.339 kg, this hose measures 0.21m in length, 0.206m in width, and 0.098m in height. Choosing a genuine OEM coolant hose ensures the correct routing geometry, precise fitment, and resistance to high temperatures and pressures, which are critical for preventing leaks and maintaining cooling system integrity.