Pentek (655005-43) 10" x 4.5" Big Blue RFFE Series Radial Flow Iron Reduction CartridgePentek Big Blue Series 10" x 4. 5" RFFE Radial Flow Iron Reduction Cartridge Mixed bed DI resin cartridge engineered to reduce dissolved iron up to 3 ppm, eliminating metallic taste and protecting plumbing fixtures from staining and scale damage Whole House Iron Reduction Pentek 655005 43 WHY IT WORKS Specialized resin media for dissolved iron removal without chemicals Radial Flow Design Water flows from outside to center through mixed bed DI resins,