FMINI Replacement Filter for Mini Max: Compatible with blue pure mini max air purifier ONLY. Not compatible with blue pure 511 411 311 Efficient H13 HEPA Filtration: The mini max HEPA filter captures up to 99.97% of airborne particles as small as 0.1 micron in the air Value Mini Max Replacement Filter Set: You'll get mini max replacement filters compatible with blue pure mini max air purifier (for 12-24 months of use) Perfect fit size for easy installation of air purifier replacement filters. We recommend replacing your air purifier filter about every 6 months Customer Service Guarantee: We are committed to customer satisfaction. Save money with XBGG mini max replacement filter! 4-Pack Mini Max Replacement Filter Compatible with Blue Pure Mini Max Air Purifier, FMINI Replacement Filter for Mini Max Air Purifier, Premium H13 HEPA Filtration System