We have 2 cats, 2 dogs, and our oldest son has asthma. He got the diagnosis almost a year ago. Since then, we have been using these filters to better the air in our home. With all the animals, and living in Georgia where pollen rules the spring, we have noticed way less animal hair, dirt and pollen in our home. We change them every 30 days, and they definitely filter a lot of crap out of the air. For areas high in pollen, or dust if you are in the desert, or if you have animals, I highly recommend these filters. Minimal dusting of furniture.l, and you can't even tell we have animals! Plus, the best part, my son breaths better.
Have been buying filters for YEARS 16 x 20, when I really need 18 x 20 - these fit nicely (much better) and will see how well they work when I change it a month - came quickly, so that was nice
1 filter was so bent and dented it wouldn't fit cleanly into furnace1 filter came with a big opening in the plastic and dust already on the filter1 filter was good