The Flat Bank air filter housing is a permanent housing designed to hold ASHRAE rated air filters. Standard filter sizes are 2" or 4" in depth. Housings are manufactured in 8-1/2" and 12" depths. This housing is fabricated from galvanized steel or -optional T304 stainless steel and is welded together and or bolted together. The unit is one-piece construction with aluminum extrusion to hold the filters in place. Upstream corner gussets increase the rigidity of the unit. Each unit is manufactured to meet specific end user requirements.