Genuine OEM Audi Coolant Hose, part number 4G0121055AC. This hose is a critical component of the engine cooling system, responsible for circulating coolant to dissipate heat and maintain the engine's optimal operating temperature. It connects various engine components, facilitating efficient heat transfer, and is shown connecting near the radiator. Weighing 0.321 kg and measuring approximately 0.455 meters in length, this hose is engineered for precise fitment and durability. Choosing a genuine OEM coolant hose ensures the correct routing geometry, material composition, and pressure resistance for reliable, leak-free performance and long service life.