BETEC CAD. model PG-B-11 is a perforated Supply / Return air grille with 3mm dia of perforations at a pitch 5mm. The perforated sheet is made of GI with powder coated finish. Also available with Opposed blade damperBETEC CAD. manufactures Grilles for air distribution in HVAC systems. They provide excellent performance for air distribution and low pressure drops at different air passage velocities. All models of Square or Rectangular Grilles are designed to give full flexibility in volume and air pattern control. Air distribution pattern can be made horizontal or vertical along the wall or ceiling. Deflecting vanes and opposed volume damper can be adjusted from the grille face. By adjusting the volume damper, flow volume can be adjusted. The volume damper is designed in a unique way that it can be used as an equalizing grid. Single or multiple length arrangement will provide positive alignment of adjacent sections using alignment strips, provided with each linear sections. The grille is constructed from high quality aluminum extruded profiles.