LifeSupplyUSA Set of 3 Air Purifier Filter fits All Blueair 500 Smoke Stop air purifiers Will fit: Blueair 501, 503, 550E, 601, 603, 650E models and ALL Blueair 500 & 600 Series Air Purifiers Heavy Carbon Filters combined with True HEPA filter Essential for households with Children, Seniors, Pets, Allergy and Asthma sufferers and smokers By LifeSupplyUSA - Brand New Individually Sealed