I DON'T BUY ANY OTHER FILTER. I HAVEN'T FOUND ANOTHER FILTER THAT WORKS AS WELL AS THIS ONE. SINCE I SUFFER FROM ALLERGIES, THIS FILTER MAKES IT EASIER TO TOLERATE IT. MY EYES DON'T ITCH ANYMORE.

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.

I've always used Filtrete since I bought my house 15 years ago but lately my spouse developed adult onset asthma and moving from the 800 to the 1200 product has made a huge difference in our air quality. Great for households with pets.

the physical dimensions are > 4", actually close to about 4.5". Be sure you're housing will accommodate 4.5" before purchasing. Can't comment on the function because these would not fit.

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!

Used the Filtrete 2200 1" MPR filter until we had the furnace/air conditioner system replaced last year which has a 4" filter but the Filtrete 4" filter maximum filtration is a 1550 MPR...wish it came in the 2200 MPR.

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

Over the years we have tried dozens of filter, since we switched to Filtrete we have not tried any others. This product works, we have cats, dog, and it keeps the air clear and fresh.

I bought the 4" filter for my heat pump and it is working great. No loss of air flow and is removing the dust from the air. Will buy another one when it needs replaced.

I have used these filters for years. They say they are good for the whole year, though I still change mine out every 6 months. Ordered through Walmart as they were the only place I could currently find them amidst all this COVID crap going on