Rectangular ventilation grille with vertical adjustable bars for
direct installation in circular ducts. The grille can be used for both
supply and exhaust air. The grille can be supplied with horizontal
directional bars, straight or slanting sliding damper or blade damper.
The grille is designed so that the grille flanges always fit tight to
the duct regardless of the duct diameter. RGS is made of hot-galvanised
steel plate and is put together without welding. This means that the
grille can be used without further surface treatment. The exterior of
the grille thus matches the duct surface.