[True H13 HEPA Filter]The filtration efficiency of 0.1 Micrometre particles is as high as 99.97%, such as pollen, pet dander. [Different from other activated carbon air filters]It has the characteristics of developed pore structure, specific surface area, strong adsorption capacity, and high strength. Easily removes indoor odors such as smoke, chemicals and volatile organic compounds (VOCs). [Excellent Performance] Features excellent noise control, workmanship, higher capacity and filter life without sacrificing for blue pure 411 air purifier performance. The Delivery Rate (CADR) after replacement is no different from the filter. [Replacement Suggestion]In order to maintain the excellent performance of your for blue pure 411 air purifier,for blue pure 411+ air purifier or mini air purifier, we recommend replacing it every 6 months or so when used 24 hours a day filter screen. Colour:White Material:Paper Package Contents: 1 x Purifier Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.