The Blueair 111230 Blue Pure F4MAX Allergen Block Air Purifier Filter is specifically designed for use with the Blueair 411a and 411i air purifiers. Made by the reputable brand Blueair, this filter effectively captures allergens and contaminants from the air to improve indoor air quality. Perfect for those looking to enhance the air purification capabilities of their Blueair air purifier, this filter is an essential component in maintaining a clean and healthy environment in your home.