Pleatco PMA45-2004-R Replacement Cartridge for Master Spas Ep (New Style), 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 6-7/8-by-4-1/16-by-4-1/16-inches Made in the USA