Linear slot diffuser- with removable pattern control device

I don't know what brand of linear diffusers I've seen, but they look more like the MetalAire LFL style In T-bar flushount grills I see a

Product Page No Linear Slot Diffuser and Linear Bar Grille Overview The grille shall have extruded aluminium inverted 'V' shaped blades and an extruded

linear slot grill Linear Slot Diffusers 6600 Series Linear Slot Diffusers ; 2000 Series Bar Grille 14 on 12 Centers ; 2100 Bar Grilles 2100 Series Linear Bar Grille ; Air Flow

linear slot Linear Bar Grille The LBG series grilles are designed to be used in air conditioning systems for either heating or cooling or a combination of both The