As a standard, the grilles are made with four sided air distribution, but on request they can be with 1, 2 or 3 directions of air discharge. Internal section of the decorative part can be easily removed, ensuring this way an approach to the regulation damper and possibility for the installation of the damper to the plenum box. The air flow rate of single ventilation diffuser can be from 100m3/h. up to 1500m3/h (27l/s – 417l/s).