Pleatco PMAX50P4-M Replacement Cartridge for Maax Spas of Canada (MICROBAN), 1 Cartridge Replacement cartridge for maax spas 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 5CH-35 and filbur FC-0300M; made in usa; microban inhibits the growth of stain and odor causing microbes like bacteria and algea Measures 5-3/4-inches in diameter 8-7/16-inches in length and 1-1/2-inches bottom hole diameter