The HEPA (High Efficiency particulate air filter) filter essentially refers to a filter that meets the HEPA standard. Because it can effectively adsorb fine particles in the air (especially 0.1 to 0.3 microns) (the adsorption efficiency is more than 99.7%), it is recognized as "indoor PM2.5 / 0.3 sterling". In addition to this, the HEPA filter can absorb fine particles such as PM2.5/0.3, and can also absorb other various pollutants such as mold, bacteria, viruses, etc., and the effect is also remarkable. In addition, for users who are close to dust in their homes or who have “old smokers” in their homes, the HEPA filter is also applicable. Its adsorption effect on dust and smoke is still strong.