DESC: The MinusA2 is designed to ELIMINATE, REMOVE and DESTROY many allergens, odors and germs. The 1st stage is the Pre-Electrostatic filter (washable), captures large size particles, dust, pet hair, and allergy germs. The 2nd stage is the Medium filter, this anti-bacterial filter traps allergens and mold greater than 1 micron in size. The 3rd stage is the RabbitAir HEPA filter which captures all airborne allergens and mold 99.97% of the time down to 0.3 microns in size. The 4th stage is your free customized "Germ Defense" filter which is specially engineered to destroy allergy germs and viruses, including the influenze virus.