... air flow, efficiency, and great capacity, long service lifeFiltration class: F5 F6 F7 F8 F9Outside size average effectRate flow volumePrimary resistanceEffective filtration ... or stainless steel and plastic. Satisfactory filtration material, and ideal milling process treatment ... , petrochemical, chemical, light industries. outside dimensionRated air flowPer resistanceAir dust counting for effect %width ...