Genuine OEM Audi HVAC Channel Adapter, part number 4M0819821C. This component is crucial for connecting and directing airflow within the vehicle's heating, ventilation, and air conditioning system, ensuring proper climate control. It is typically located on the rear left side. Made from durable, lightweight plastic, it measures approximately 0.22m long. Opting for a genuine OEM adapter guarantees precise fitment and optimal airflow characteristics, maintaining the efficiency and performance of the HVAC system.