Pleatco PA175-4 Replacement Cartridge for Hayward Star-Clear Plus C1750, Sta-Rite PXC-175, 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 28-3/8-by-4-by-4-inches Made in the USA