The AH 200, AH 280 range of back filter exhaust grilles are used for exhausting and filtering air in air-conditioning and heating systems in service sector, residential and industrial premises. They are composed of a series of fixed, parallel, horizontal, aluminium profiled blades, angled at 40° (AH 200) or an aluminium 12.5 x 12.5mm square mesh grille (AH 280) and a natural extruded anodised aluminium frame suitable for holding a 12mm thick filter cell with mechanical closure via a hidden spring. For ceiling installation, versions AH 200/N and AH 280/N are available, with mechanical closure via hidden safety screw. The front section is hinged onto the frame. The nominal 570 x 570mm size model is particularly suitable for surface mounting onto 600 x 600mm panel false ceilings.