ULTIMATE TOOL AGAINST WILDFIRE SEASON: Additional activated carbon removes 99.9% of wildfire smoke along with extra protection against other wildfire emissions such as toxic gasses, smog and odors COMPATIBLE WITH ENTIRE BLUE PURE 411 AIR PURIFIER LINE: Blueair 411 Series SmokeBlock Replacement Filter compatible with entire Blue Pure 411 air purifier line consisting of Blue Pure 411 Auto, Blue Pure 411, Blue Pure 411+ air purifiers FILTERS BUILT TO LAST: Using a 360-degree air intake and up to 4x the filter surface area the Genuine Blue Pure 411 Series SmokeBlock Filter lasts on average 6 months; optimizing air flow and performance over time REMOVES EVEN TINIEST AIRBORNE PARTICLES DOWN TO 0.1 MICRON: Particle filter removes airborne particles such as pollen, pet dander, bacteria, mold, viruses, and dust from your indoor environment TRAPS HOUSEHOLD ODORS: In addition to wildfire emissions, active carbon mesh also traps household odors, smoke, chemicals, and volatile organic compounds (VOC) BLUEAIR AIR PURIFIERS ARE INDEPENDENTLY TESTED FOR PERFORMANCE and SAFETY, ZERO OZONE: AHAM Verifide for CADR; Ozone Safety Standards Certified by CARB