Genuine OEM Volkswagen Fuel Supply Hose, part number 3Q0131961D. This hose is a component of the reducing agent fuel supply system, typically used for delivering AdBlue or Diesel Exhaust Fluid (DEF) to the emissions system. It is designed to withstand the specific chemical properties and pressures of the fluid. Genuine OEM parts ensure the correct material composition, flexibility, and connection integrity for reliable operation and compliance with emissions regulations.