pleatco PCC80-PAK4 Replacement Cartridge for Pentair Clean and Clear Plus 320, Pack of 4 Cartridges 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 20-1/6-by-3-by-3-inches Made in the USA