1) High efficiency HEPA grade, with minimum efficiency of 99.97% at 0.3 microns (based on D.O.P. tests) 2) One layer, two layer High efficiency HEPA filter is individually certified to have a minimum efficiency of 99.97% at 0.3 microns (based on D.O.P. tests). For capturing problem particles of dust, pet dander, mold and bacteria, the TEDA vacuum filter media are up to 12 times more efficient ...