Genuine OEM Volkswagen Reduction Agent Tank Ventilation Union, part number 2E0201485. This small but vital union provides a secure connection point within the reduction agent (AdBlue/DEF) tank's ventilation system, ensuring proper pressure equalization and preventing system malfunctions. Weighing only 0.003 kg, this genuine OEM component is engineered for precise fitment and chemical resistance, crucial for the reliable operation of the vehicle's emissions control system.