Fiberglass filter paper 1.made from glass microfiber 2.efficiency:99.9999% 3.performance of water repellency or anti-virus Glass microfiber filter media, comprised primarily of glass microfibers, is produced with a wet laid process which is similar to that used in the production of paper. Our offerings range from various ASHRAE grades (F6-F9), HEPA grades (H10-H14) to ULPA grades (U15-U16) with ...