Replacement filter cartridge used for a pool, hot tub or spa. Measurements: Length:  25 1/2" Diameter:  7" Top Opening:  3" Bottom Opening:  3" Popular brand part numbers: Unicel: C- 7487 Filbur:  FC-1270 Pleatco:   PA100N Features: Free Flow Core 100 Square feet of filter media By Guardian Filtration Products in the USA   Alternative filter names:  CX870-XRE,  CX870RE,  C-870RE,  Super-Star-Clear C4000,  Super-Star-Clear C4020,  Super-Star-Clear C4025,  Super-Star-Clear C4000S,  17-175-1037,  APCC7179, 19902, FC-6445  PA100N-4,  PA 100N,  PA100-N,  SD-00551, 090164710044 Used in pools/spas made by:   Hayward and other manufacturers