This Refrigerator Water Filter is used in top freezer refrigerators with filter access in the base grille. Simply turn the filter 1/4 turn to remove and replace. This NSF® Certified filter reduces chlorine taste and odor, 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 2301705, W10312235 & 4396702.