Product Description Previously known as Pur Ultimate Blue 3 Stage Filter. Filters up to 100 Gallons/378 Liters (2-3 months) Stage 1: Added layer to trap sediment Stage 2: Contaminant removal The activated carbon filter removes 99.9% of microbial cysts, Cryptospordium and Giardia. In addition reduces Lead, Asbestos, Benzene, MTBE, and TTHMs. Stage 3: Filtered over natural minerals for a Crisp, Refreshing taste. Leaves beneficial fluoride in the water. This pur filter reduces Heavy Metals (Lead and Mercury), Chlorine (taste and odor) and Benzene to provide clean, healthy, great tasting water. Reduces these ChemicalsSources of Contaminant in Drinking WaterPotential Health Effects from Ingestion of Water LeadCorrosion of household plumbing systems: erosion of natural depositsInfants and children: Delays in physical or mental development. Adults: Kidney problems; high blood pressure. Total TrihalomethanesByproduct of drinking water disinfection.Liver, kidney or central nervous system problems; increased risk of cancer. References "Current Drinking Water Standards" US EPA (available at epa.gov/safewater/mcl.html) NSF International, a nationally recognized, not-for-profit agency for the certification of water filters, has tested and certified this product to reduce the following list of contaminants. Products with the NSF mark are certified to pass a series of stringent independent tests. System Tested and Certified by NSF International against NSF/ANSI Standard No. 53 in model numbers FM3400, FM3700, FM3800, FM4100, FM4400, FM7300, FM7400, FM7500, FM7600, FM9100, FM9300, FM9400, FM9500, FM9600, FM9700, FM9800, FM9900 for the reduction of: 2,4-d, 2,4,5-TP (Silvex), Alachlor, Asbestos, Atrazine, Benzene, Carbofuran, Carbon Tetrachloride, Chlordane, Cysts, Endrin, Ethylbenzene, Heptachlor Epoxide, Lead, Lindane, Mercury, Methoxychlor, Monochlorobenzene, MTBE, o-Dichlorobenzene, Simazine, Styrene, Tetrachloroethene, Toluene, Trichloroeth