FLUORIDE AND ARSENIC REDUCTION FILTERS - These authentic Berkey PF-2 Fluoride and Arsenic Reduction Elements replacement filters are designed for use in conjunction with authentic Black Berkey BB9-2 and Phoenix Gravity New Millennium Edition Filter Elements to adsorb fluoride, arsenic(V) and pre-oxidized arsenic(III), and other residual typical heavy metal ions. FILTERS TO REDUCE A BROAD ARRAY OF CONTAMINANTS - Included Phoenix Gravity New Millennium Edition Filter Elements have been tested by independent third-party labs to remove or reduce 200+ typical waterborne contaminants found in U.S. and global municipal water supplies. THE ONLY OFFICIALLY ENDORSED REPLACEMENT FILTER - Buy with confidence—Phoenix Gravity New Millennium Edition Filter Elements are the only filter officially endorsed by New Millennium Concepts, Ltd. for use in Berkey water systems in lieu of Black Berkey Elements (BB9-2). Phoenix Gravity New Millennium Edition Filter Elements can be used with all Berkey systems and most other brands of gravity-fed filter systems. ECONOMICAL, LONG-LASTING FILTERS - We recommend replacing Phoenix Gravity New Millennium Edition Filter Elements every 2,750 gallons (5,500 gallons per set of 2 filters). Filters may require replacement sooner based upon the quality of influent water. Berkey PF-2 Fluoride and Arsenic Reduction Elements should be replaced after 1,000 gallons of use, under normal conditions. INCLUDES PRIMER FOR FAST, EASY FILTER SETUP - PrimeEasy Universal Primer stretches and adapts to most faucet heads and spigots to ensure a smoother, more efficient priming experience by giving you a sealed, leak-resistant connection when running water through filters before first use. Authentic Berkey PF-2 Fluoride and Arsenic Reduction Elements replacement filters are designed for use in conjunction with Phoenix Gravity New Millennium Edition Filter Elements and Black Berkey BB9-2 Filter Elements and to adsorb fluoride, arsenic(V) and pre-oxidized arsenic(III), and other residual typical heavy metal ions. Phoenix Gravity New Millennium Edition Filter Elements address more than 200+ typical contaminants found in U.S. and global municipal water supplies.