Made for people with the most severe allergies and asthma, our MERV 13 air filters are designed to remove the tiniest particles from your indoor air. Filters of this MERV rating and higher are typically reserved for hospitals and clean rooms but can also be used in your home. They are more than 90% efficient at capturing particles that are 1.0-10 microns and up to 75% efficient at capturing the 0.3-1.0 micron particles (see chart below for examples). Heavy-duty beverage board is used to construct the frame to insure the filter stays in place. A 100% synthetic fiber media that will not support any microbial growth is also utilized. The service life of these MERV 13 filters is 30-90 days dependent upon the conditions in your home. Read more about this on our "Air Filter Change Frequency" page. Use the filter finder at the top of the page to find your size.