Genuine OEM Volkswagen Fuel Supply Hose for Reducing Agent, part number 3Q0131961F. This hose is a critical component of the vehicle's selective catalytic reduction (SCR) system, responsible for transporting the reducing agent (such as AdBlue or Diesel Exhaust Fluid) from the tank to the injection point in the exhaust system. It is constructed from materials resistant to the reducing agent and designed for precise routing and secure connections to prevent leaks and ensure proper system function.