Airfoil’s Door Grilles are manufactured with the highest quality, lightweight, corrosion free anodised aluminium. This type of grill utilises extruded aluminium inverted “V” type blades that have a free area of approximately 65% which ensures maximum air flows at minimum sound levels. The door grille comes complete with an adjustable frame and spring clips that fit into the rear of the door insert to provide a flush appearance. Suitable for a 30mm to 45mm door thickness. It is recommended for doors, walls or partitions whenever a site-proof return, relief or any transfer is required.