【PERFECT COMPATIBILITY】:Blue Pure F2MAX Replacement filter 𝐏𝐞𝐫𝐟𝐞𝐜𝐭𝐥𝐲 𝐅𝐢𝐭 𝐟𝐨𝐫 𝐁𝐥𝐮𝐞 𝐏𝐮𝐫𝐞 𝟐𝟏𝟏𝐢 𝐌𝐚𝐱 Smart Machine. 𝐍𝐨𝐭 𝐜𝐨𝐦𝐩𝐚𝐭𝐢𝐛𝐥𝐞 𝐰𝐢𝐭𝐡 𝟐𝟏𝟏+, 𝟐𝟏𝟏+ 𝐀𝐮𝐭𝐨, 𝟑𝟏𝟏𝐢 𝐌𝐚𝐱, 𝟑𝟏𝟏𝐢+ 𝐌𝐚𝐱, 𝟒𝟏𝟏𝐢 𝐌𝐚𝐱, 𝟓𝟏𝟏, 𝟓𝟏𝟏𝐢 𝐌𝐚𝐱. Please check the models of your machines 【HIGH QUALITY MATERIAL】: Blue 211i Max replacement filter is made of high-quality non-woven fabric and activated carbon. The white particle filter helps absorb 99.97% of airborne particles,dust, dander, lint etc (with a diameter as small as 0.03 micrometers) and the activated carbon filter efficiently works for wildfire gases, car exhaust, smoke, strange smell, pet odor etc.Bringing you healthy environment 【EASY TO INSTALL】: You just need to take out the old dirty 211i Max replacement filter compatible for blueair and change it with new one and the replacement will be done. No additional tool is needed, really simple 【REPLACE the FILTER EVERY 6-9 MONTHS】: To guarantee you always enjoy the fresh ai-r, we kindly suggest you replace the filter every 6-9 months based on usage to maintain optimum performance of the machine 【CONTACT US WITHOUT ANY HESITATION】: NXBHG Store has been specializing in bringing each family freshing air with providing customers premium quality and affordable replacement filter. We highly value customers' shopping experience and If you have any problems while using this replacement filter compatible wtih 211i Max replacement filter, please contact NXBHG Store customer service team without any hesitation. We are ready to help you to solve problems within 24 hours. 211i max Replacement Filter