I have a high end portable air purification system that I purchased. The air filter is now needing to be changed after about 4 months. I know exactly what kind of air filter to get, but when I looked it up and went to buy it online I found that it was almost 30 bucks! What? 30 bucks for an air filter for a portable air purification system? That is highway robbery if you ask me! However, taking into consideration that it is a HEPA brand air filter, that may be the reason why. And HEPA air filters are of the utmost high quality when it comes to air filters for portable air purification systems, central heating and a/c system units and even vacuum cleaners! So I feel I will just go ahead and pay the high price for the HEPA brand air filter for the portable air purification system. It is the only air filter that will fit into it and update the old one. So I am kinda stuck with having no choice. I mean the high end portable air purification system that I purchased is undoubtedly high end and works actually great, and most of that is because of the HEPA brand air filter that comes in the portable air purification system. And if I have to dump this money down every 5 months or so, it doesn’t bother me I guess. It will be worth it to keep the indoor air quality going great in my kitchen while I am trying to sleep.