Pleatco PSR15-4 Replacement Cartridge for Sta-Rite TX-15, 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-1-1/16-by-1-1/16-inches Made in the USA