Pleatco PMA30-2002-R Replacement Cartridge for Master Spas EP-Cylinder (Old 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 7-1/4-by-4-by-4-inches Made in the USA