The Ac-9966 features Ionizer and a 4-Stage filter assembly: Pre-Filter (Pp Mesh Filter), cutting-edge Plasma Technology (Tungsten Filament plus Grounding Net), Voc filter and Hepa filter. Targeted to effectively remove smoke, dust, pollen, PM2.5, bacteria, mold and virus in a 1,000 cu.ft. space. Both Hepa and Voc filters are designed to operate continuously for up to 3,000 hours.