Pleatco PWWPC125-4 Replacement for Waterway Proclean In-Ground Pool Cartridge 125-Square-Foot, 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 23-1/4-by-4-by-4-inches Made in the USA