Blueair Blue Pure AllergenBlock Filter – Genuine Replacement for Blueair 211i Max Air Purifier – Traps Allergens, Pet Dander, Pollen, Dust, 10″ x 20.7″ x 4.7″

Customers find the air filter effective, with one mentioning it helped with seasonal allergies, and they appreciate its quality and easy installation. The filter performs well at reducing smoke and odor, particularly from litter boxes. While some customers consider it worth the price, others find it too expensive.