The Helios Fans RVE 200 is a practical solution for retrofitting ventilation systems, designed for straightforward insertion into existing ventilation pipes. It features a robust plastic ring with an all-around double lip seal to ensure an airtight fit. The valve incorporates a tight-fitting rubber membrane that opens in response to negative or positive pressure, allowing controlled airflow as needed. Two different membranes are supplied to offer varied flow rates, enabling adaptability for different ventilation requirements. For installations with horizontal airflow, it is important to position the web holding the rubber membrane vertically to maintain correct function. The RVE 200 is suitable for operation within a temperature range of ‑20°C to +90°C, accommodating a wide range of environments.