The AC-9966 features Ionizer and a Four-Stage filter assembly: Pre-Filter (PP Mesh Filter), cutting-edge Plasma Technology (Tungsten Filament + 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. There are airborne diseases caused by viruses or bacteria. Improving indoor air quality and ventilation can reduce the exposure to and transmission of airborne diseases. An air purifier can play a key role to improve air ventilation****. *Tested by Intertek. **Tested by Intertek. 99.9% reduction of Escherichia coli and Staphylococcus epidermidis and Aspergillus niger. Test period: 30 minutes. ***Tested by Intertek. 99.9% reduction of Phi X174 Bacteriophage. Test period: 30 minutes.****The air purifier cannot offer complete protection on its own. Other prevention of airborne transmission of infections includes vaccinations, wearing personalized protective equipment (like masks), and performing basic infection prevention measures (like hand washing). The tests did not measure whether the air purifier was able to prevent transmission of the virus or bacteria from person to person.