Genuine OEM Volkswagen Fuel Tank Cap, part number 1C0201550AD. This cap is designed to securely seal the fuel tank opening, preventing fuel evaporation, contamination, and ensuring the integrity of the vehicle's evaporative emissions system. It is a black plastic cap with an integrated tether. Choosing a genuine OEM fuel tank cap guarantees a precise fit and proper sealing, which is crucial for maintaining fuel system pressure, preventing check engine lights, and ensuring safety.