Pleatco PGS25P4 SPG Replacement Cartridge for After Hours Spas, Nemco Spas, Threaded 25-Square-Foot Top Load, 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 9-3/4-by-1-1/2-inches MPT with handle Made in the USA