This is a replacement filter for the Clearly Filtered Stainless Steel water bottle made of a proprietary blend of activated coconut carbon and adsorption media that lasts up to 100 gallons. To put that in perspective, one filter will generate more pure water than 750 disposable half liter bottles. With bottled water prices now costing as much as 2,000 times tap water, this bottle filter allows you to save money while saving the planet! This filter is rated to filter up to 99.99% of contaminants from all fresh water sources. Filter filters up to 90% of Fluoride from municipal tap water and is also rated for biological elements in outdoor water sources. Filter is not rated for viruses.