Genuine OEM Volkswagen Reduction Agent Tank Cap, part number 2E0201553D. This cap is designed to securely seal the opening of the reduction agent (AdBlue) tank, preventing contamination, spillage, and evaporation of the fluid. It is essential for maintaining the purity and effectiveness of the AdBlue system. Made from durable black plastic and weighing 0.071 kg, it includes a tether to prevent loss. Choosing a genuine OEM tank cap ensures a perfect seal, chemical resistance, and long-term durability for the emissions system.