This Refrigerator Water Filter is used in side-by-side and top mount refrigerators with filter access inside the refrigerator. Simply turn the 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. Replacing this filter every 6 months ensures clean, safe drinking water. Replaces 8171788.