Pleatco for Dynamic Series IV - DFM, DFML, Series II and III RTL/RCF-50, Series I RDC-50, RDC-50S, Waterway, (MICROBAN), 1 Cartridge Replacement filter for pool and spa cleaning systems 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-4950 and filbur FC-2390M; made in usa; microban inhibits the growth of stain and odor causing microbes like bacteria and algae Measures 5-inches in diameter by 13-5/16-inches in length and 2-1/8-inches of top and bottom hole diameters