1 Air Purifier replacement Filter fits ALL Blueair SmokeStop 400 Models 401, 410B, 403, 450E,400PF, 401PF ; By LifeSupplyUSA Fits ALL Blueair 400 Models 400PF, 401, 401PF, 410B, 402, 403, 410 450E, 455, 455EB Includes Activated Carbon layer fortified with Magnesium Dioxide and Copper dioxide True HEPA Filter Prevent bacteria and mold growth and filters out gas and odor Brand New Individually Sealed - By LifeSupplyUSA