11 Air Distribution Products and Air Terminal Equipment-Namely, Diffusers, Grilles, Troffers, Registers, Plenums, Louvers, Dampers, Extractors, Equalizing Grids, Duct Transition Adaptors, Duct Collars, Air Outlets and Inlets, Throttling Terminals, Fan Induction Boxes and Terminals, and Sound Attenuators