Pleatco PWW50-XP4 Replacement Cartridge for Waterway Front Access Skimmer, 1 Cartridge Replacement PWW50-XP4 filter cartridge 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-1.9-inches Keyed with handle Made in the USA