The Model TR is designed to be used where round connections are desired on normally rectangular grilles and or diffusers. The Model DSC-L is designed to be used where equalization pressure chamber for proper diffuser performance is desired. It also serves as a quality sound chamber.
The Models P-N, P-L, and P-EX, are custom built plenums for diffusers. These plenums can have multiple inlets and different shaped inlets The model P-N is non-insulated, the model P-L is internally insulated, and the model P-EX is externally insulated. (Shown with cable operated dual inlets).