Catalytic Carbon/KDF-85 AND 5 Micron Sediment Big Blue Whole House Filter Set - 4.5" x 20" GREAT FOR HYDROGEN SULFIDE REMOVAL Includes 5 mic. Big Blue sediment filter AND Big Blue Catalytic Carbon/KDF-85 iron & sulfur filter Filters remove sand, chlorine, hydrogen sulfide, iron, heavy metals, and unpleasant tastes & odors Fits all standard 4.5" x 20" Big Blue whole house systems Upgrade your carbon filter to the Catalytic Carbon/KDF-85 filter for excellent sulfur removal