Genuine OEM Volkswagen Ad Blue Reservoir Filling Neck, part number 2K5131965A. This component provides the access point for refilling the Ad Blue fluid, which is crucial for the selective catalytic reduction (SCR) system to reduce nitrogen oxide emissions. The assembly includes the main filling pipe and associated hose connections. Weighing approximately 0.594 kg, it is constructed from durable plastics and rubber to withstand automotive fluids and environmental conditions. Choosing a genuine OEM filling neck ensures a perfect seal and correct connection to the Ad Blue reservoir, preventing leaks and maintaining the integrity of the emissions system.