Aprilaire 401 Replacment Filter for Aprilaire Whole House Air Purifier Model: 2400, Space Gard 2400, MERV 10 (Pack of 4) BUY WITH CONFIDENCE This genuine replacement filter was designed and manufactured in the U.S.A. by Aprilaire  the leader in indoor air quality solutions OPTIMIZES THE PERFORMACE of your Aprilaire or Space Gard Air Purifier Model 2400 CREATE A HEALTHIER HOME by preventing airborne allergens from circulating through the air in your home. Remove common airborne allergens from the air as it passes through the MERV 10 filter including dust, pollen, mold spores, bacteria, pet dander, and dust mites WORRY FREE We stand behind the performance of our air filters with our 10-year Clean-Coil Commitment SAVE TIME & UPGRADE PERFORMACE Consider the Aprilaire 2400 Upgrade Kit. It replaces the original 401 filter with a high performance 413 replacement filter and new filter frame system, eliminates pleat spacers