Item Type: High Efficiency Particulate Air Filter Element_x000D_ Material: High efficiency particulate arrestment and cotton_x000D_ Applicable: For Blueair Pro M L XL 1APPLICABLE MODEL: Compatible with for Blueair Pro M, L and XL air purifiers(Pro M is 1 filter, Pro L is 2 filters, and Pro XL for 3 filters) 2REMOVE POLLUTANTS: True filtration effectively catch harmful ultrafine pollution particles as small as 0.1 microns and catch up to 99.97% of air pollutants from the air 3FOR ALLERGIC PEOPLE: This air purifier filter element is great for people allergic to dust, pollen, pet hair and dander 4HYGROSCOPIC COTTON: Adopt excellent cotton material, which is porous, hygroscopic, heat resistant, you can use with confidence 5STABLE AND DURABLE: Air purifier filter element come with stable structure, excellent performance and long service life1 x FilterElement