Water filtration for the great outdoors! The rugged 22 oz. Sport Berkey bottle is great for everyday use at home, work or school. Or, enjoy filtered water while you're off-grid, traveling abroad or in emergencies. The Sport Berkey Bottle filter uses the same filtration formulation as Black Berkey Elements, which are used in our popular outdoor gravity-fed systems. We recommend replacing the filter after 160 refills of untreated water, or 640 refills of tap water. The Sport Berkey water filter bottle has been tested by multiple independent third-party labs for its ability to remove or reduce typical contaminants found in tap water or other freshwater sources like lakes and ponds.