Hunter HP670 True HEPA Air Purifier filter that can capture up to 99.97% of airborne particles as small as 0.3 microns, including smoke, dust, pollen, pet hair and dander, mold spores, and dust mite debris. But that's not all - the EcoSilver® pre-filter contains silver nanoparticles that prevent the growth of microorganisms on the filter, including bacteria and viruses. Plus, the coconut carbon in the pre-filter neutralizes harmful VOCs and household odors from cooking, cleaning, smoking, and pets.