H11 HEPA Replacement Air Filter for XF180 Fume Extractors, Box Style Air PurifiersAdvanced Features: XF 180 REPLACEMENT FILTER: This 4 pane filter is the exact replacement true HEPA filter for OMTech's industrial strength series XF 180 fume extractors. For optimal filtration, choose only original OMTech filters for your machine! HIGH EFFICIENCY: Our 7. 6" x 7. 6" x 7. 7" inch air purifier box filter is capable of clearing 99. 9% of particles as small as 0. 5 microns including dirt, dust, soot, smoke, and other contaminants, keeping