This replacement filter cartridge has the technical specifications of Unicel # C-7487, Pleatco # PA100N-4, Filbur # FC-1270 and OEM # CX870XRE and it is best fit for Hayward Super-Star-Clear C4000, Swim-Clear C4020, Super-Star-Clear C4000S. With 25 ½ inch of length and 7 inch width it can handle the top load of 100 sq. ft. It has 3 inch open holes both at top as well as bottom. It provides you clean and clear water for your swimming pools as spas.