Replacement Pool & Spa Filter: C-7375 (73531, 77813, FC-3964, PCD75N, 77515) filter cartridge features 75 square feet 15 inches of 3-ounce basis weight media that catches debris and particles, keeping your hot tub water clear.  Compatible with Hawaiian, Olympia, Salina, Makena, Moorea, C-30 & C-45. 2000-2004 Aspire, Tahitian, Niagra, Geneva & Elation spas.