Blueair Blue Pure 311i+ Max AllergenBlock Filter, Genuine Replacement for Blue Pure 311i+ Max Air Purifier

BOOST ALLERGEN PROTECTION: AllergenBlock defense layer neutralizes over 90% of the allergen properties such as sneeze-inducing dust, pollen and pet dander that can trigger discomfort* | UPGRADE YOUR DEFENSES: Blue Pure 311i+ Max Series AllergenBlock Blueair filter is designed for optimal performance; Compatible with 311i+ Max air purifier* | SNEEZE-INDUCING ALLERGENS: Four layers of air purifier filtration; AllergenBlock defense layer neutralizes over 90% of pollen, dust and pet dander on the Blueair filter; Carbon layer reduces light household odors* | AUTOMATED FILTER REPLACEMENT: Subscribe and save up to 10% on auto-delivered filters when replacement is needed; When used 24 hours a day, your Blueair filter should be replaced every 6 months to effectively reduce airborne pollutants and allergens | Product Dimensions 17.7 x 13.4 x 3.7 inches