The last two filters that I purchased for my refrigerator lasted only one month each. Water from the door slowed to a very slow rate. The product (filter # 4) states that it will last 6 months. Water to my 2018 Tiffin Allegro Bus passes through two carbon filters and a water softener before the refrigerator. Replacing the filter with the by-pass plug the water flow increases to an expected flow rate.