Venti Air Perforated T-bar Drop Ceiling Step Down Supply or Return Diffuser with R6 Insulation Back, Needs Start or Tab Collar

T-Bar drop ceiling step down perforated diffuser is designed for 360° high volume air supply or return air grille for commercial or large areas. It comes with molded r6 insulation with vapor barrier. It does not have a collar and needs a start or tab collar to connect the diffuser to the duct. The collar can be from 4 in. to 14 in. Dia. The diffuser is colored white and can coordinate with most backgrounds.