The WaterBasics GRN Line Filter Water Bottle keeps you safe from waterborne illness when you need it. Easily refill it over 500 times from any natural water source or questionable municipal water supply. The bottle includes a convenient finger ring for easy filling and carrying. The bite valve says clean thanks to the rigid dust cap. Squeeze the bottle to assist the flow of water through the filter. The bottle comes with a Series II GRN Line Filter and is certified to EPA and NSF/ANSI standards for the removal of bacteria, Cryptosporidium, Giardia, chlorine, chemicals, taste and odor.