Whole House Heavy Metals Well Water Filter Replacement Set – 3 Stage Sediment Kdf/Blend Carbon Block 20 In. Removes up to 99% of pollutants for safety and reliability. Fits any regular 4.5 in. Three-stage whole house system. Offers a filtration life of up to 100,000 gal for versatile use. Remove pollutants from your water with this Whole House Heavy Metals Well Water Filter Replacement Set – Three Stage Sediment KDF/Blend Carbon Block 20 in. It is designed to remove up to 99% of contaminants. This includes chlorine, lead, mercury and more. Removes up to 99% of chlorine, water-soluble lead, mercury, nickel, chromium and other dissolved metals. Original filters for PRO-100-E three-stage whole house, heavy metals well water filtration system. Upgrade any standard 4.5 in. Three-stage whole house system to an iron sulfur and heavy metals filtration unit. Filtration life of up to 100,000 gal. Safe water as soon as you install and flush the filters.