Genuine OEM Volkswagen Reduction Agent Metering Line, part number 5Q0131984AE. This specialized line transports reduction agent, such as AdBlue or DEF, from the metering unit to the exhaust system for effective emissions control. It is typically located in the front section of the vehicle, within the emissions system assembly. Weighing 0.154 kg, this line measures 0.35m in length. Using a genuine OEM metering line ensures proper fluid resistance, precise routing, and leak-free operation, which is critical for the integrity and efficiency of the emissions system.