The ducts in my house require 2 filter sizes not available at home supply stores. I was very happy to find these available on line. They both fit, and were delivered promptly. They are made in America. Ive gone through several deliveries, and they seem to work (asthma and allergies are better indoors), and they all fit. They look the same as commercial brands
The site lists the MERV 13 filter as optimum, but fails to warn that a MERV 13 filter could stress out older systems and act just like a clogged filter.If there really was any care about the choice or type of filters the site would help to point this fact out. Of course they won't because they are only interested in moving product.