What's the difference between an AC Vent Cover and a Linear Slot

What's the difference between an AC Vent Cover and a Linear Slot linear slot vent TRUaire LD Linear Slot Diffusers linear slot diffuser installation detail Displacement Ventilation · Flexible Ducts · Grilles · Single Louver Grilles · 301RL Linear Slot Diffuser Description Linear slot diffusers model MLC are

linear slot diffuser installation detail Linear slots get used mostly on perimeter spots, usually above large window areas for entrainment that is, so the supply air can mix with whatever heat load

linear slot diffuser cfm chart Expella's Linear Slot Grille is an internal ceiling diffuser designed for use with ducted inline ventilation systems which sits discreetly on the ceiling  Expella's Linear Slot Grille is an internal ceiling diffuser designed for use with ducted inline ventilation systems which sits discreetly on the ceiling