The Filbur FC-2394, Dakota 45 Pool & Spa Filter replaces Unicel part number C-4311, and Pleatco part number PDS 45. Also known as part numbers FC2394, C4311, PDS45, and Dakota Spa 45. The Filbur Pool and Spa filters are made of Reemay spunbound polyester pleated filter media with thermally bonded polyurethane caps and punched PVC pipe cores ensuring durability and consistent flow. All Filbur Pool & Spa Filters also feature Anti-Microbial technology, or Microban Technology, which prevents microbes, such as bacteria, mold, fungi, and mildew from growing or reproducing. Microban Technology is becoming an industry standard and is featured in all Filbur Brand Pool & Spa filters.