Pleatco PMT50 Replacement Cartridge for Sonfarrel 50-220152, Cal Spas, Martec, Advantage Manufacturer, 1 Cartridge Replacement cartridge for sonfarrel 50-220152, cal spas, martec and advantage manufacturer 50 Percent open ABS free flow cores maximize water flow through reemay filter media Antimicrobial end caps resist chlorine degradation and provide support to filter material for a longer life span Replaces unicel C-4305 and filbur FC-1617; made in usa; microban inhibits the growth of stain and odor causing microbes like bacteria and algea Measures 5-inches in diameter 14-3/4-inches in length and 2-1/8-inches of top and bottom hole diameters