The tinman supply air ductwork plenum is a rectangular-shaped product made of 26 gauge galvanized steel. It measures 16 x 25 x 12 inches and is compatible with various HVAC systems such as ducted evaporative coolers, packaged/rooftop furnaces, and central air conditioners. It can be installed in both updraft and downdraft configurations. The product comes in a unit quantity of 20.
eBay