The true HEPA filter captures up to 99.97 percent of particles as small as 0.3 microns, including allergens, such as pollen, dust, pet dander, and smoke. Antimicrobial treatment provides built-in protection from the growth of odour and stain-causing micro organisms. Compatible with AeraMax Pro AM2 Air Purifier. One-year estimated filter life, depending on usage conditions. 1 filter per pack.