FITS: C4326 UNICEL C-4625 SPA FILTER FC237 PLEATCO PRB25 Single Pack Cartridge 25 sq ft Bottom Opening: 2 - 1/8" Top Opening: 2 - 1/8" Outside Diameter: 4 - 15/16" (also replaces 5") Length: 13 - 5/16" Replacement for Unicel C-4326 Expansive Flow Core. Break resistant Banding 3oz REEMAY Filtration Fabric