Genuine OEM Audi Coolant Hose, part number 427121107B. This hose is designed to transport coolant efficiently throughout the engine cooling system, playing a vital role in maintaining optimal engine temperature. It connects to the coolant expansion tank. Weighing 0.115 kg and measuring 0.396 m in length, this genuine OEM hose provides the exact routing geometry and material resistance required for a durable, leak-free connection.