SINGLE FILTER NEW IN FACTORY PACKAGING MADE IN THE USA Antimicrobial filter material inhibits bacterial growth on the filter surface. This makes the filter easier to clean. Also replaces the following filters: Watkins 30 / Hot Springs - OEM Part # 31489 / 71825 / 71826 / 75041 / 73178 / Tri-X / 0969601 / APCC7095 / 13004 / APCC7095M Unicel - C-6430 (C6430) Filbur - FC-3915 (FC3915) Pleatco - PWK-30 (PWK30)