Replacement Filter for Blueair Blue Pure 411/411+ & Blueair 3210 Air Purifier True H13 HEPA Filter with Activated Carbon Filtration efficiency of 99.97% for particles as small as 0.1 micrometers, including pollen and pet dander Features a developed pore structure, large specific surface area, strong adsorption capacity, and high strength Effectively removes household odors such as smoke, chemicals, and volatile organic compounds (VOCs) Designed for superior performance with excellent noise control, craftsmanship, higher capacity, and extended filter life without compromising air purifier efficiency Clean Air Delivery Rate (CADR) remains consistent with original filter performance after replacement Recommended to replace every 6 months when used 24 hours a day to maintain optimal air purifier performance Compatible with Blueair Blue Pure 411, Blueair Blue Pure 411+, and Mini air purifiers Please verify your air purifier model before purchase Color: White Material: Filter paper + activated carbon cotton Package Contents: 1 x Replacement Filter Note: Lighting and display differences may cause slight color variations between the image and actual item Measurement allowance: +/- 1-3 cm