This replacement filter cartridge complies with the technical specifications as Unicel # C-4321, Pleatco # PRB25-IN-TC, Filbur # FC-2372 and OEM # 17-2653. This 13 5/16 inch long and 4 15/16 inch wide filter cartridge is closed from the top and has open hole of 2 1/8 inch open hole at the bottom. This filter cartridge is capable of handling the top load of 25 square feet and is the best fit for Pentair Pool Products-Rainbow Pl, Leaf Canister. By adopting this filter for your pools and spas you get complete protection from germs and sand and also get clean and clear water. Very easy to install this filter cartridge is made of high quality of materials.