Our MERV 11 air filters are a great upgrade from MERV 8 air filters if you have pets in your home or suffer from allergies or asthma. These air filters are 85% efficient at capturing particles in the 3-10 micron range (see examples in the chart below) and up to 80% efficient at capturing particles in the 1.0-3.0 micron range (see chart below). The filter frame is constructed of heavy-duty beverage board to insure it maintains its integrity for the duration of its service life. The pleated media won't support microbial growth due to its 100% synthetic construction. Our MERV 11 air filters have a 30-90 day life depending on the conditions in your home. Check out our "Air Filter Change Frequency" page for additional information. Use the filter finder at the top of the page to find your size.