This Refrigerator Water Filter is used in side-by-side refrigerators with filter access in the base grille. Simply turn the Refrigerator Water Filter 1/4 turn to remove and replace. This NSF® Certified filter reduces cysts, asbestos, chlorine taste and odor, particulates (class I), lead, and mercury. The contaminants or other substances removed or reduced by this water filter are not necessarily in all users' water. Replace every 6 months ensures clean, safe drinking water. Replaces 4396548, 4392922, 4396164, 2203221, & 2255709.