HEMCO HEPA Filter Paks effectively collect particulate contaminants from the exhaust air stream. HEPA filters are 99.999% effective at removing particulate .3 micron and larger. The filter pak housing features a hinged access door with gaskets and spring latches for convenient filter change. Inlet and outlet plenums with duct connection collars are installed. The HEPA Filter Pak can also be paired with a carbon filter pak to remove chemical fumes and odors.