This Replacement filter cartridge complies with the technical specifications as Unicel # C-7489, Pleatco # PA112, Filbur # FC-1275 and OEM # CX875RE. This 25 ½ inch long and 7 inch wide filter cartridge has 3 inch open holes both at the top as well as bottom. It is capable of handling the top load of 112 sq ft and is most suitable for Hayward Super-Star-Clear C4500, SwimClear C4520. Very easy to install and this filter cartridge is made of top quality materials.