NSF/ANSI 42 Certified Black Purification Elements, for BB9-2® Water Filters Replacement, Compatible with Berkey Gravity Filtration System, Replacement for Berkey Black Filter, Pack of 2[Black Purification Elements]: The Water Filter for BB9 2 Replacement Uses High Quality Natural Coconut Shell Activated Carbon. We Carefully Select Filtration Materials And Use Lead Free, Bpa Free Materials To Ensure Excellent Filtration Performance And User Safety [High Efficiency Filtration]: Replacement for BB9 2 Water Filters Effectively Reduce Fluoride And Arsenic, Absorb Odor, Color, Residual Chlorine, Heavy Metals,They Also Reduce Sediments And