The Nu Series carbon block cartridges. Made from high density activated carbon provide superb filtration up to 5 micron. Especially recommended for the removal of heavy chlorine contamination. It improves the taste and smell of the water, as well as eliminating organic contaminants, pesticides and other chemicals. The filtration area of carbon block is almost double that of regular granulated carbon, therefore it has larger adsorption capacity and longer filtration life. Cartridges have polypropylene jacket to prevent the escape of minute carbon particles. They are highly recommended for use with Reverse Osmosis systems. Cartridge in testing phase Combination of the Coconut Shell Activated Carbon with the KDF Media makes this candle type cartridge unique and universal. Activated carbon removes chlorine and organic pollutants, KDF55 Process Media exchanges electrons with contaminants turning them into harmless components, such as chlorine into chloride. KDF also creates an unfavorable environment for bacteria growth as well as extends the working qualities of activated carbon.