Pleatco PH6-4 American, Harmsco ST/6, Pac-Fab, Premier, Rainbow, Swimquip 6, 108, 216, 72, SwimRite, Universal Six, 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 9-13/16-by-1-1/16-by-1-1/16-inches Made in the USA