[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, surface area, strong adsorption capacity and high strength. remove household odors, such as smoke, chemicals, and volatile compounds(VOCs).[Superior Performance]Has noise control, workmanship, higher capacity and filter lifetime without sacrificing blue pure 411 air purifier performance.The delivery rate(CADR) after replacement is no different from the filter.[Replacement recommendation]In order to maintain the performance of your blue pure 411 air purifier, blue pure 411+ air purifier or mini air purifier, we recommend changing the filter 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 .Attention: check your air purifier when you buy it.Material: Filter paper + activated carbon cottoncolour: WhitePackage Contents:2 x FilterOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real . The measurement allowed is +/- 1-3cm.