By not being a cheapskate I ended up discovering the best air filters for our central heating plus cooling system unit. For just a few bucks more than the typical air filters I used to buy I was able to get a pack of HEPA air filters for our central heating plus cooling system unit, but these HEPA air filters are the best ever! I have never had air filters that were this great. They keep the air quality wash plus they last a bit longer than the respected air filters I used to buy. I was more than glad paying a few bucks more just to be able to try these out. Because now I will be buying HEPA air filters all of the time. HEPA air filters are now our choice air filter to use when I need to change the filter in our central heating plus cooling system equipment unit. There is no way I would ever go back to the outdated air filters I was using because HEPA air filters are far superior to those other air filters, however make no mistake folks! When it comes to buying air filters for your central heating plus cooling system equipment unit the only way to go in our humble opinion is to buy the HEPA brand air filters. There is nothing else in the world love it plus I do not think I would ever be able to top these HEPA air filters no matter what else there was. All the hype you hear about HEPA air filters is one hundred plus ten percent true. I had our doubts too originally.