2-Pack H13 True Hepa + Activated Carbon 2-In-1 Filters | | Compatible With Blueair Blue Pure 411I Max And 411A Max Air Purifier F4Max (Not Compatible With 411, 411+ And 411 Auto Air Purifier) | | H13 True Hepa Capture Up To 99.97% Of Airborne Particles As Small As 0.3 Microns. This Includes Dust, Pollen, Pet Dander, Smoke, And Other Minute Particles ,Activated Carbon Reduce Chemicals Vocs, Tobacco Smoke, Pm2.5,Common Household Bad Smell | | Please Replace Regularly To Keep Your Machine Fresh And Clean. For The Best Performance, Clean The Filter Once A Month With A Soft Brush Gently Or With A Vacuum Cleaner. | | Top-Notch Quality Used For Maximum