Filter says 16x25x4 but it is actually 4.25 thick! Does not fit in my furnace which is exactly 4.0" This is an extremely frustrating problem and every store carries the new 4.25 filter and apparently nobody makes or carries the old 3.75's anymore. I could cram a 4" in there but not one thats 4.25. Trust me, I tried.

[This review was collected as part of a promotion.] I have used this 4" filter since replacing our furnace (used 1" Filtrete filters before this). Love how it cleans the air, especially since we have 2 Balinese cats. The only "con" about this filter is how hard it is to remove from the furnace. I finally figured out a way to attach a string to the front of the filter so that it's an easy pull-out when it needs to be changed. Perhaps Filtrete could come up with something like this, or 2 finger holes for easy removal.

I am asthmatic so CLEAN AIR is not a low end necessity for me - it is a HIGH END necessity. I am very happy with my indoor air quality and knowing that I am able to stay healthier with cleaner air is double payback. I share with all people I come in contact with that what type of house air filter you use to clean your air DOES matter.

I had my doubts when I bought this filter but after just a few days we can tell a difference its making in our home. The air is fresher, cleaner and our babies are having less allergy problems. I love this product and will continue to purchase them.

I change my filter that every two months. Every time I change my filter with this product I see the nastiness it keeps my family from breathing in. I wouldn't trust any other brand!

This air filter does a better job of trapping all the junk in the air of our house. It located in a very clean walk-in closet and we're at what it catches. Its especially effective during the spring pine tree pollen season

[This review was collected as part of a promotion.] My go to ! Super easy to put in, best preforming and doesn't fall apart! Works well with our unit! Makes our maintenance super easy my 8 years can do it !

I upgraded from the Allergant Protector (also a great filter) just to see if I could tell a difference. I can! The air seems cleaner and it gives me peace of mind knowing that it helps with bateria and viruses.

This is the only product I purchase for our furnace. I particularly like that it only requires changing once a year. When we changed ours for 2024 we discovered that it could have remained in place longer.

If only installed the filter a month ago, therefore the 4 star rating. Once it's been in for 6 months I'll see how it performed compared to the others I've used.