The Black Berkey Elements provide top-notch water filtration, addressing over 200+ contaminants that may be present in tap water and fresh water sources such as rivers and ponds. With independent, third-party testing, you can trust the quality and performance of these filters. Each pair of Black Berkey Elements lasts for up to 6,000 gallons, with the option to add additional pairs (sold separately) for even more contaminant reduction. The Black Berkey Elements are both economical and long-lasting. Don’t settle for less when it comes to your water quality – choose the unmatched performance and quality of Black Berkey Elements.