The 45° hinged louver air grille is mainly used for return air and exhaust air, commonly installed on fan coil units and ceiling-mounted air handling units. It comes with a filter mesh and can also be fitted with opposed-blade dampers, installed in supporting combination with supply air outlets.  
The face profile sizes are available in 25 mm and 30 mm. Materials include aluminum alloy, iron plate and stainless steel, with custom dimensions selectable by customers.