I bought this to replace my 3M whole house filter (4WH-QSS-F01H). Installation instructions were provided with the filter. This was nice as it is a MUCH tighter fit than 3M. Knowing this beforehand was great. After installing, I turned on many of my second floor fixtures to flush and remove air from pipes. After installation, if I used more than one fixture at a time I had noticeable pressure loss. If I opened three faucets then water would barely come out. I never had this problem with any of my 3M filters. American Filter advertised this as a 10 gpm filter (same as 3M) but there is NO WAY I could flow 10 gpm through the filter I received. I tried to call the customer service number twice and never got an answer. I am currently bypassing the filter so I can use more than one fixture at a time. I WOULD STRONGLY ADVISE AGAINST BUYING THIS FILTER AS A REPLACEMENT FOR THE AFOREMENTIONED 3M FILTER! Unless you live by yourself or only have one bathroom in your home.

Had one filter that was bad. You sent out a new one right after I emailed. I received the replacement within a week. I sent the defective filter back. Pleased with your quick response. Merry Christmas!

The filters fit perfectly.

Your website is easy to maneuver through, the descriptions are well written and I was able to find the filters I needed without having anxiety. I was confident that I was going to get the correct filter. Thank you