This Whirlpool W10413645A refrigerator water filter features a PUR Water Filtration System and can be used in refrigerators with filter access inside the refrigerator. Simply turn the filter to remove and replace. While retaining beneficial fluoride, this filter is NSF Certified to remove/reduce chlorine taste & odor, particulates, lead, cysts and 5 additional contaminants. The contaminants or other substances removed or reduced by this water filter are not necessarily in all users' water. For freshest water and optimal performance, replace water filter every 6 months.