... 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 ... , long life (washable), economical, utility, easy to install.Filtration efficiency class: G3, G4, F5, F6, F7, F8 Portable Of Vacuum Cleaner Filter