Genuine OEM Volkswagen Fuel Tank Cap, part number 3D0201550AF. This cap is designed to securely seal the fuel tank opening, preventing fuel evaporation and protecting the fuel system from contaminants. It is specifically marked for Diesel fuel. Constructed from durable plastic and weighing 0.075 kg, using a genuine OEM cap ensures a perfect seal and proper pressure regulation, which is critical for fuel system integrity and emissions control.