[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, 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 Blue Pure 411 air purifier performance. The delivery rate (CADR) after replacement is no different from the original filter. [Replacement Recommendation] In order to maintain the excellent performance of your Blue Pure 411 air purifier, 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 Blue Pure 411 air purifier, Blue Pure 411+ air purifier and Mini air purifiers. Attention: Please check your air purifier model before purchasing. Color: white. Material: filter paper + activated carbon cotton. Package Contents: 1 x Filter. Only the above package content, other products are not included. Note: Light 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.