Don’t let allergens get the best of you and your family. This Filtrete True HEPA Room Air Purifier Filter traps 99.97% of all airborne particles, including dust, allergens, bacteria and viruses. You can enjoy the benefits of this Filtrete Filter even if you have a Idylis air purifier. (Disclaimer: as small as 0.3 microns, from the air passing through the filter media. Initial efficiency value.)