Filters out ultrafine particles >20 nanometers**
**In combination with the multi-care filter, the HEPA filter filters out ultrafine particles >20 nanometers including bacteria, dust, allergens and some viruses. According to publications of World Health Organization, the avian influenza, human influenza viruses and Legionella bacterium are larger than 20 nanometers.
Healthy air protect lock ensures healthy air always
Healthy air protect lock function ensures you healthy air always. It shuts off the purifier when healthy air can no longer be guaranteed. When one of the filters is almost full and has to be cleaned or replaced, the Healthy air protect alert warns you to replace or clean filter. When users do not replace concerned filter, the appliance stops operating and the appliance is locked.