[True H13 HEPA Filter] The filtration efficiency for 0.1 micrometre particles is as high as 99.97%, such as pollen, pet dander. [Unlike Other Activated Carbon Air Filters] It has the characteristics of developed pore structure, large specific surface area, strong adsorption capacity and high strength. Easily remove household odors, such as smoke, chemicals, and volatile organic compounds (VOCs). [Superior Performance] Has excellent noise control, workmanship, higher capacity and longer filter lifetime without sacrificing Blueair Blue Pure 411 air purifier performance. The clean air delivery rate (CADR) after replacement is no different from the original filter. [Replacement Recommendation] In order to maintain the excellent performance of your Blueair Blue Pure 411 air purifier, Blueair Blue Pure 411+ air purifier or mini air purifier, we recommend changing the filter every 6 months or so when it is used 24 hours a day. [Matching Model & Attention] Suitable for Blueair Blue Pure 411 air purifier, Blueair Blue Pure 411+ air purifier and Mini air purifiers. Attention: Please check your air purifier model before purchasing. Colour: White Material: Filter paper + activated carbon cotton Package Contents: 1 x Filter Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture to be slightly different from the real thing. The measurement allowed error is +/- 1-3 cm.