Genuine OEM Volkswagen AdBlue Filler Tank Cap, part number 3C0131980. This cap is designed to securely seal the AdBlue (Diesel Exhaust Fluid) filler tank, preventing contamination from dirt and debris while also minimizing evaporation. It is a small, black plastic component with an integrated handle for easy removal and installation. Weighing 0.0301 kg, it measures 0.049m in length, 0.049m in width, and 0.052m in height. Choosing a genuine OEM cap ensures a precise fit and a reliable seal, which is crucial for maintaining the integrity and effectiveness of the vehicle's emissions system.