Pleatco PVT25N-P Replacement Cartridge for Vita Spas Duet, 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 7/5/8-by-1-1/2-inches MPT with closed top Made in the USA