[This review was collected as part of a promotion.] I have been purchasing 16x25x4 filters for years. 3M recently changed the filter design (thick paper stock casing has no diagonal elements) but also the width. As a result the filter width is 1 centimeter too narrow and thus leaves a gap through which unfiltered air can go into the blower. My observations are consistent with what another user's review from early August 2025 is describing, and their photos clearly show the difference in width between the previous and new designs of the filter. At the very least you should indicate clearly on the label that the filter is narrower than previously. I know you made 2 versions of a 16x25x4 in the past (regular and slim; the regular version fits my furnace). Are you now only making narrow versions?

Bought this a month ago after having my unit replaced. I was suffering with severe allergies due to the ductwork and unit being replaced by a very sloppy company, so I decided to give it a shot (it had its work cut out for it) I am replacing it today. Usually lasts a lot longer but my home was contaminated severely due to the negligence of our ac repair company!

[This review was collected as part of a promotion.] My nephew stays with me from time to time. He has asthma, which seems to act up on high pollen days. We can have the windows up with the air off and he would need breathing treatments. A couple of minutes with the windows shut and the air being on, lil man is back to normal.

I've been using this type filter almost 3 months, and I've got to tell you that it's a great improvement over reusable filters that I was using. You can see all of the particles it collected...yes, it is DIRTY! I couldn't really see the dirt on the washable ones. I've noticed that there is less dust collecting in the house' big plus! Haven't noticed reduction of airflow nor higher energy bills. I'll continue using this filter...a little expensive to me- but we'll worth it!

This is the best filter for keeping the animal allergens under control. I put in a new one in the furnace yesterday before relatives with dog allergies came over and they had no problems the entire evening. So great! Better, too, for us non allergy people to not be breathing in all those minute particles.

Excellent air filter. I buy these 20x20x1 sizes and tape them to a regular box fan for a quick, easy, and affordable air filtration unit that I can move around the house wherever/whenever I want. No need for any special high end unit that requires a unique filter that some company stops supporting.

We've been using The Filtrete Allergen Reduction filter #12 for about 6 months now and it does seem to be helping us with our allergies by cutting the amt. of allergens in the house. The Filter also fits perfectly so there is no noise from an ill fitting filter...we've had this problem in the past, but not at all with Filtrete. The dimensions are exactly what they state. Excellent filter. High recommend it.

[This review was collected as part of a promotion.] This is absolutely the best air filter I have found for my home. We had some minor construction in our kitchen, Sheetrock, taping and sanding. Dust was everywhere. Installed one of these Filtrete Healthy living filters and the air quality improved within minutes. I change my filter every season, the Healthy Living filters trap so much dust, dander and who knows what else. Great product worth the price!

The Filtrete 1550 Allergy Reduction filter does a remarkable job in filtering out the seasonal mountain allergens that blow into our North Central TX home. We use fewer antihistamines since we have installed the high efficiency filters. Thank you, 3M.

Upon advice from my doctor to purchase a better a/c filter, I researched and purchased two of these. We quickly noticed a difference in the air quality, my headaches and sneezing are much better now. I am allergic to dust mites and my cats dander - I am extremely impressed. When I clean, there is far less dust accumulated on surfaces in my house which is lovely. After changing the filter recently we found out why - this filter is blocking everything. So great! We are considering investing in higher grades of the Filtrete brand because this one has done so well.