... filtration efficiency Air purification CE/ISO/UL/ROSH Vacuum cleaner filter is Widely used as the pre-filtration and single- ... internal combustion engines.Excellent chemical fiber nonwoven used as the filter core materialABS, PP, PC, PVC plastic frame, or two ... dust holding capacity, long life (washable), economical, utility, easy to install.Filtration efficiency class: G3, G4, F5, F6, F7, F8 Portable ...