I've tried a lot of different filter makers. The Allergen Defense 1200 made a HUGE difference in just 6 hours after I installed it. My headache went away and the nasal drip stopped! I'm a true believer in my improved health!

This filter removes all of the smells we've gone nose blind to over time. The other day I cooked some fresh fish and ran out for an errand. When I came back I could not tell what we had for dinner. Can't say the same at my neighbor's house!

We have been using these for years, living in Florida and believe that these filters keep down the amount of pollen from outside and dander from our 2 dogs inside.

We have been using the Allergen Defense filter for over a year and I have noticed a dramatic reduction is the particals of dust in our house. That means less time I have to devote to dusting the floors and furniture.

I have asthma and allergies. I have used Filtrete for many years. There is a noticeable difference in air quality while in use. Just wish they were a little less expensive.

bEEN BUYING THIS PRODUCT FOR YEARS NOW AND I'M NEVER DISAPPOINTED. THE AIR IN THE HOUSE ALWAYS SMELLS CLEAN. I HAVE ALLERGIES BUT THEY DON'T PERSIST WHILE I'M IN MY HOUSE. THEY ARE NOT CHEAP BUT WELL WORTH IT

The Filtrete products are the best 4 inch filter I've ever used. Would recommend it to anyone else not happy with their current product. Less dusting is always appreciated. My allergies are thankful too.

This Filtrete filter was recommended by my hvac installer and it’s worked great for me. I tried a cheaper brand and my allergies seemed to be noticeably worse. I only with they made the 20X25X4 in the smart option.

I've used various filters and found this model to be very effective. Amazed at what it actually catches from the normal air. Noticeably helps during the allergy seasons (severe hayfever).

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.