Specification Brand : APRIL-FLOWER BulletPoint1 : Compatible Models: The 411i Max, 411a Max, and F4MAX replacement filters are compatible with Blueair Blue Pure 411i Max, 411a Max, and F4MAX Air Cleaner to maintain their peak performance. Fit snugly with the machine. It works as well as the original with the same performance, keeping your 411i Max, 411a Max, and F4MAX Air Cleaner at its best working efficiency and capacity. Any use of the brand name or model designation for this product is made solely to demonstrate compatibility. BulletPoint2 : Not Compatible Models: 411, 411+, and 411 Auto. BulletPoint3 : Premium Material: Our 411i Max, 411a Max, and F4MAX replacement filter is made of high-quality non-woven fabric with premium True HEPA and activated carbon materials to greatly improve the performance of 411i Max, 411a Max, and F4MAX filter replacement. We adopt advanced lower energy consumption and lower density structure technology, higher efficiency, and less pressure to ensure high-efficiency filtration. BulletPoint4 : 3-In-1 Stage Filtration System: Our 411i Max, 411a Max, and F4MAX True HEPA replacement filter is combined with a high-efficiency filtration system that has 3 layers of advanced filtration that removes high levels of fine particles and reduces odors. Fine Pre-filters can capture large particles of material such as hair, and pet plush. An extra protective layer of coating True HEPA filter captures 99.97% of airborne dust down to 0.3 microns in size, like dirt, dust, and pet dander. The activated carbon filter helps with household odors from pets, cooking, smoke, and so on. BulletPoint5 : Replacement Frequency: 2 Pack 411i Max, 411a Max, and F4MAX True HEPA Filters fully meet your needs for the replacement of 411i Max, 411a Max, and F4MAX True HEPA Filters. To maintain optimal performance, We recommend that you replace your 411i Max, 411a Max, and F4MAX True HEPA Filter every 4-6 months. Meanwhile, the filter's usage time will depend on the environment and air quality around you. BulletPoint6 : Easy Installation: It is fairly easy to install the 411i Max, 411a Max, and F4MAX air filters, no tools are required. Take out and replace your machine unit when needed. BulletPoint7 : B0BN2LH4RK, B08KPJQBQT, B08KPJ7SCC, B08KPHR6C2, B08KPH4PJF, B0BN2HZX1C Color : White CompatibleDevices : Compatible With 411i Max 411a Max F4MAX Replacement Filter IncludedComponents : 411i Max 411a Max F4MAX Replacement Filter ItemName : Blueair 2-Pack Pure 411i/411a Max Replacement Filter - True HEPA, Activated Carbon, Compatible With Blue Pure 411i/411a Max Air Cleaner ItemPackageDimensions_Height : 35.7886 centimeters ItemPackageDimensions_Length : 16.1036 centimeters ItemPackageDimensions_Width : 24.7904 centimeters ItemTypeKeyword : air-purifier-accessories Manufacturer : APRIL-FLOWER Material : Non-woven fabric, True HEPA MinimumEfficiencyReportingValue : 16 ModelName : 411i Max 411a Max F4MAX Replacement Filter ModelNumber : 411i Max 411a Max F4MAX Filter NumberOfItems : 2 PartNumber : 411Max_Filter ProductDescription : Features 2 Pack Blue Pure 411i Max 411a Max F4MAX Replacement Filter Compatible With Blueair Blue Pure 411i Max 411a Max Air Cleaner. For Blue Pure F4MAX Filter. 3-in-1 True HEPA Filter Activated Carbon Filter Kindly Note: This is not an OEM product and is not covered under any OEM manufacturer's promise. Any use of OEM brand name or model designation for this product is made solely for the purposes of demonstrating compatibility.