Explanation of Linear Diffusers sizes and design

What's the difference between an AC Vent Cover and a Linear Slot linear diffuser vs slot diffuser The QPRO Linear Slot Diffuser is Australian made with unique air pattern control design, suitable for supply or return air, with fully adjustable blades The linear bar grille vs linear slot diffuser HVAC linear slot diffusers are a type of ventilation system used to distribute conditioned air

linear slot diffuser catalogue Linear Slot Diffusers · Five slot widths are available—12, 34, 1, 1-12 and 2—with number of slots ranging from one to eight slots · Multiple frame styles