Blueair Blue Pure F2MAX AllergenBlock replacement filter ensures your air purifier maintains peak performance. Specifically designed for compatibility with the Blue Pure 211i Max model, this high-efficiency filter captures 99.97% of airborne particles as small as 0.3 microns, including pollen, dust, pet dander, and smoke. The multi-filtration system combines an activated carbon layer to neutralize odors with an H13 True HEPA filter for superior particle removal. Easy to install with a simple rotate-to-unlock design, this genuine replacement part helps keep your indoor environment fresh and clean.