※the HEPA replacement filter is designed to compatible with blueair blue pure 211+ air purifier.<br> ※The advanced polypropylene filter media captures up to 99.97% of particles as small as 0.1 microns in size from your indoor air and resists clogging and won't re-release particles back into the air.<br> ※Ensure continued dependable performance of Blueair air purifier while maintaining the air clean for yr health and balance.<br> ※This is not an OEM product and is not covered under any OEM warranty. Any use of the Blueair brand name or model designation for this product is made solely for purpose of demonstrating compatibility.<br> ※Recommended the replace every 6 months or depended on usage.<br>