The Helios Fans RVE 125 is designed for straightforward retrofitting by inserting directly into ventilation pipes. It features a robust plastic ring with an all-around double lip seal to ensure a tight and secure fit. The valve is equipped with a tight-fitting rubber membrane that opens in response to negative or positive pressure, facilitating effective airflow management. The product includes two interchangeable membranes for different flow rates to suit varying ventilation requirements. For horizontal airflow installations, the web supporting the rubber membrane must be positioned vertically to maintain proper operation. The RVE 125 functions reliably within a temperature range of ‑20°C to +90°C, suitable for a wide range of environments.