This replacement filter cartridge has the technical specifications as Unicel # C-4429, Pleatco # DSF25-50, Filbur # FC-3082 and OEM # C4429. This filter cartridge is best fit for 30 square foot and is best for Nemco. This 10 3/8 inch long and 4 15/16 inch wide filter cartridge has 2 1/8 inch open holes both at the top as well as bottom. By installing this filter cartridge you can get clean and clear water for your pools and spas. Very easy to replace this filter cartridge is made of superior quality of materials.