Filbur FC-1230 25 Sq. Ft. Filter Cartridge 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 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.The Filbur FC-1230 is compatible with hot tubs, pools and filters made by Hayward, Hollibaugh Spas, Pdc Spas, Phoenician Spas, Sonoma Spas and others. Original Manufacturer part number CX-250RE, CX250-RE.