Genuine OEM Audi Coolant Pipe, part number 4L0121399. This pipe is designed to transport coolant efficiently within the engine cooling system, contributing to proper temperature regulation. It is specifically located on the left side of the cooling assembly, connecting to a heat exchanger. Weighing approximately 0.1077 kg, this component is engineered for durability. Choosing a genuine OEM pipe ensures correct routing geometry, material integrity, and resistance to thermal cycling and pressure fluctuations for reliable, leak-free operation.