We set out on a two year quest to produce the most efficient air filter on the market, and we achieved it. The benchmark was set by independently testing the latest offerings on the market to set the bar. We would not be satisfied until we could state that our filters are more efficient than any other at sub-micron levels. Our testing is done to industrial standard which is much more stringent and defined than standard automotive standards. The unique dual media layup of the Desertcraft severe duty air filter is the key to it's superior filtration. It is a dry element that needs no oil and can be easily serviced and re-used for years of service.