This Replacement filter cartridge replaces Unicel # C-4302, Pleatco # PSS17.5 and Filbur # FC-0183 and complies with OEM # C4302 specifications. It is capable of handling the top load of 12 square foot and most suitable for Pleatco skim filter, Softsider Spas, Comfort Line Spas. With its length of 4 5/8 inch and the same width it provides complete protection from germs and sands in your spas. This filter cartridge has molded cone handle at its top while 1 9/10 inch hole at the bottom. Very easy to install this filter cartridge is made of high quality materials which provide you clean and clear water for your spas.