Ceiling Revisory Ventilation Diffusers TANGRA RG are especially suitable for suction grilles of fan coil units or duct air conditioners for concealed ceiling mounting. Diffusers consist of a frame from extruded aluminum profiles with incorporated panel made of perforated metal sheet. Panel lies freely on the frame and can be easily dismounted ensuring this way access for repair and revision of the equipment installed above diffuser. Diffusers are mounted to the air duct system with plenum box and flexible duct. The air flow rate of air ventilation grille can be 100m3/h up to 1200 m3/h (27l/s – 333l/s).