410 Replacement Filter for AprilAire Whole House Air Purifiers - MERV 11, Clean Air & Dust, 16x25x4 Air Filter (Pack of 4). VACUUM AND DUST LESS OFTEN by preventing airborne particles from settling on your furniture and flooring. This AprilAire 410 replacement air filter removes airborne particles as they pass through the MERV 11 filter including dust, pollen, mold, spores, bacteria, and pet dander. BETTER PERFORMANCE thanks to the patented AprilAire Self-Seal Technology which minimizes the amount of air bypassing the filter. EASY AS 1-2-3 TO INSTALL in the unique AprilAire Interlock Rail System.No assembly or cardboard or metal reinforcements needed. NOMINAL AIR FILTER SIZE of 16 x 25 x 4 inches (nominal size is an industry standard filter size system to help you easily identify the correct replacement filter and is not the actual size). PROUD PARTNER OF THE AMERICAN LUNG ASSOCIATION in support of its mission to save lives by improving lung health and preventing lung disease.