Aluminium ventilation grilles OAS are primarily used for sidewall applications and are suitable for both air supply and exhaust. The sturdy frame is made from gently sloped aluminium profiles, offering high mechanical strength and low weight. The blades are aerodynamically shaped to reduce pressure drop and noise. Sound power levels are measured in accordance with EN ISO 5135. A wide range of accessories is available, including airflow regulators, rear mounting frames, and filters.