The IonFlow Signature removes the smallest and most harmful particles such as allergens, bacteria, dust, mold, traffic pollution and smoke all the way down to 0.007 microns. Scientifically proven by third-party governmental tests. It protects against microbes in the air, such as virus, bacteria and mold. This makes it an efficient air purifier for allergy, asthma, COPD, pregnant, infants, children, and other people sensitive to influenza and other infections. According to a seven years scientific research study LightAir IonFlow air purifiers render 97% of viruses harmless immediately in the air making sure they will never bother you. The unit will not interrupt your activities or precious sleep! Put it in a bedroom or office and no one will be disturbed! Operates at 21 decibels (compared to 35-80 decibels for HEPA filter systems).