Durable Carbon Steel Construction with Baked Enamel Finish and Powder Coated Weather hood, Fully Drawn Weather hood - No Welds to Rust or Vibrate Apart, Paper Element: 99% + Removal Efficiency Standard to 5 Micron, Tubular Silencing Design - Tube is Positioned to Maximize Attenuation and Air Flow While Maintaining Pressure Drop, Interchangeable Media: Paper, Paper, HEPA, Several Element Sizes Available, Temperature Range : -15°F to 220°F, Filter Changed Out Differential 10-15" H2O Over Initial Delta P.