Pleatco Replacement Cartridge for American Commander 100, Hayward Star-Clear 100, Hercules II, 100-Square-Foot; 4-Ounce, 1 Cartridge Replacement filter for pool and spa cleaning systems 50% 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 29-3/8-by-3-by-3-inches Made in the USA