The frame shall be made of a rigid high-density 3/4” particleboard or 18-gauge galvanized metal, (26-gauge galvanized metal frame is used for the Magna 950 Series – 95%). A 26-gauge galvanized steel header is available on the metal frame on 950 Series. The media shall be constructed of a water-resistant, inorganic glass microfiber. For quality assurance, the glass microfiber media rolls are randomly tested and certified to meet minimum efficiency requirements by the media manufacturer. The media pack shall consist of a continuous sheet of the pleated glass microfiber. The pleated media pack is separated with multiple rolled-edge corrugated aluminum separators. The media cartridge shall be sealed with a fire retarding, rubber base, two-part sealant that bonds the media and separators to the interior of the frame. A 1/4” thick closed cell neoprene gasket shall be applied on the filter. The filter shall be rated to withstand temperatures at a continuous 180o Fahrenheit. The 95%, 99.97% and 99.99% Magna filters shall be U.L. Classified.