2 AUTHENTIC BLACK BERKEY ELEMENTS BB9-2 REPLACEMENT ELEMENTS FOR BERKEY GRAVITY-FED WATER FILTER SYSTEMS- Black Berkey Elements can be used with Big Berkey, Berkey Light, Crown Berkey, Imperial Berkey, Royal Berkey, Go Berkey and Travel Berkey Systems. FILTERS OVER 200+ TYPICAL CONTAMINANTS THAT COULD BE PRESENT IN TAP WATER- Choose only Black Berkey Elements. There are no substitutes for Berkey performance and quality. INDEPENDENT TESTING- Black Berkey Elements are composed of a unique, proprietary blend of multiple media types backed by testing from accredited, third-party labs. Black Berkey Elements are designed to work synergistically and target specific contaminants that far exceed the reduction capabilities of carbon block filters that are solely composed of activated carbon. ECONOMICAL, LONG-LASTING- Black Berkey Elements provide filtered water for just pennies per gallon. Each pair of Black Berkey Elements lasts for up to 6,000 gallons before replacement is recommended. Elements may require replacement sooner based upon the quality of influent water. THE GOLD STANDARD IN GRAVITY-FED WATER FILTRATION- Authentic Black Berkey Elements are capable of greater contaminant reduction and a longer lifespan than virtually any of the other filter elements on the market.