Genuine OEM Audi Engine Coolant Return Pipe, part number 03G121151AB. This pipe is a critical component in the engine cooling system, responsible for circulating heated coolant from the engine back to the radiator for cooling. It is typically routed through the engine bay, connecting various cooling system components. Constructed from durable, heat-resistant materials, it weighs approximately 0.52 kg and measures about 0.63 meters in length. Choosing a genuine OEM coolant pipe ensures correct routing geometry, proper sealing, and resistance to high temperatures and pressures, preventing leaks and maintaining cooling system integrity.