Pleatco PBF50-F2S Replacement Cartridge for Bullfrog 50, 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 5-7/8-by-2-inches with handle Made in the USA