Berkey systems are designed to meet the speci?c needs of consumers seeking practical and cost-e?ective water ?ltration solutions. Berkey systems are simple and easy to use and require no electricity, costly installation, or tools, providing economical, long-lasting water ?ltration for just pennies a gallon. Berkey systems are used every day in homes around the world by discerning consumers who trust the quality of Berkey systems to meet their drinking water needs. Berkey gravity-fed water systems are available in 7 sizes. From the Manufacturer Berkey Systems are the World's Most Powerful and Cost Effective Personal Water purification Systems Providing Reliable and User-friendly Water Purification in Both Normal and Hostile Filtration Environments. Moreover, Berkey systems are capable of purifying both treated water and untreated raw water from such sources as remote lakes, streams, stagnant ponds and water supplies in foreign countries, where regulations may be substandard at best. So powerful, this system is able to remove red food coloring from water without removing the beneficial minerals your body needs. Perfect for everyday use and a must in hostile environments where electricity, water pressure or treated water may not be available.