The tinman supply air duct plenum is a rectangular-shaped product made of galvanized steel with a 26 gauge thickness. It is compatible with various HVAC systems such as ducted evaporative coolers, packaged/rooftop furnaces, and heat pump split systems. The plenum can be installed in both updraft and downdraft configurations and measures 16"x19"x24" in length. This product is sold in a unit quantity of 20.