Rejuvenate your air purifier with this Blueair HEPA particle filter. Its polypropylene and activated carbon materials ensure particles are trapped and odors and gases are removed, while the antibacterial fibers maximize the removal of pet dander, pollen, mold and mites. The gradient structure of this Blueair HEPA particle filter resists clogging, so the purifier doesn't re-release particles back into the air.