Nature-Pure Ultrafine^™ Water Purifier is the only chemical free purifier of its type certified to meet the EPA Guide Standard for Microbiological Purification by removing bacteria, cysts and virus. Nature-Pure water purifier also excels at chemical and aesthetic contaminant removal. Importantly, Nature-Pure water purifier is environmentally friendly, working without electricity, chemicals or wasted water. Plus Nature-Pure purifier doesn't need large storage tanks, double-processing or hold time.