The filter works like a magnet to draw in and trap contaminants as they pass through the straw, leaving only clean, fresh water. Our filters are made out of activated carbon and a unique formulation of ion exchange materials that provide the greatest contaminant reduction in the industry. All our filters are made in the USA out of the following materials:ACTIVATED COCONUT CARBON: Absorbent carbon derived from coconut shells that remove organic compounds and pollutants from water. As contaminated water passes through the filter, absorbent carbon media trap and neutralize waterborne pollutants. These toxins include disinfectants like chlorine, solvents, PCB’s, PBDE’s, and compounds that cause bad taste and odor.CRM ION EXCHANGE MEDIAS: A blend of proprietary media bonded in a chelative matrix to effectively remove heavy metals, industrial and agricultural pollutants, and trace pharmaceuticals. Using adsorption, absorption, chemical bonding, chelation, and depth filtration, our unique formulation of activated carbon and ion exchange materials turns ordinary tap water into great-tasting, filtered water.