The Helios Fans WSG 70/40 is a wall grille designed to cover intake and exhaust air openings, preventing the entry of rain, snow, and animals. Sized to fit Helios duct fans, it fits securely into the cross-sectional area of the ducting. The grille is built from extruded aluminium with a natural anodised finish, ensuring durability and corrosion resistance. Fixed louvres spaced at 65 mm intervals guide airflow effectively, while a galvanised sheet steel mesh grill with a 16 mm mesh width is set behind the louvres to offer additional protection without hindering ventilation.