The addition of the DOP filter makes the DefendAir HEPA 500 a high efficiency three-stage air filtration unit, ready for any sensitive job requiring first-pass HEPA filtration.

This 20-gauge galvanized metal frame measures 24 x 24 x 2 inches.

Guardian Carbon Filter Frames are an improved and more economical way to provide gas and odor filtration. This 20-gauge galvanized metal frame is sized to fit the Phoenix Mini-Guardian. It measures 16" x 16" x 2".