The Helios Fans ZLE 100 features a manually adjustable poppet valve combined with an integrated air filter cassette and a robust external shutter, all manufactured from impact-resistant polymer. Airflow direction can be adjusted in four steps via a ratchet mechanism operated by a pull cord, allowing easy manual control. The valve’s interior includes an insulating lining to prevent condensation buildup. Additionally, this model provides effective sound attenuation between 30 and 35 dB, supporting quiet and efficient ventilation performance.