Pleatco PCS50N-M Replacement Cartridge for Coleman Spas 50 (MICROBAN), 1 Cartridge Replacement cartridge for coleman spas 50 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-8450 and filbur FC-3310; made in usa; microban inhibits the growth of stain and odor causing microbes like bacteria and algea Measures 8-inches in diameter by 9-inches in length and 2-1/8-inches of top and 2-inches of bottom hole diameter