Genuine OEM Audi Coolant Hose, part number 4L0121081A. This hose is an integral part of the engine cooling system, responsible for transferring coolant between various engine components to maintain optimal operating temperatures. The diagram shows it connecting to a cooler assembly. Weighing approximately 0.104 kg and measuring 0.27 m in length, this hose is constructed from durable rubber. Choosing a genuine OEM hose ensures precise fitment, proper routing, and resistance to high temperatures and pressures, which are vital for the longevity and efficiency of the cooling system.