Features: Saves energy with passive airflow Controls wind blast and prevents draughts irrespective of wind direction Provides over 5000mm2 equivalent area when used with most duct sizes Internal grille has manually controllable internal closing plate plus fly mesh Safely prevents gas spillage caused by side winds Can be used in new build and retro-fitted in refurbishment … Continue reading ArrestAir-Pro Plus DiffuseAir for Background Ventilation