The Katadyn MyBottle water purifier is the simple solution for making water potable when traveling abroad or setting out on a lightweight backpacking trip. Simply fill the MyBottle from a tap or a lake, screw the cap on and start sipping; 3-stage purification process eliminates viruses, bacteria and protozoa. Purifier utilizes a carbon filter, glass fiber cyst cartridge and a ViruStat iodinated resin cartridge to eliminate contaminants, including giardia and Cryptosporidia. Carbon pre- and post-filter improves the taste of stale, swampy water. Bottle can be filled 155 times before it is necessary to replace the purifier cartridge; replacement purifier cartridges are sold separately. Food-grade polyethylene plastic bottle and cap are 100% BPA free; bottle holds 24 fl. oz. of water after displacement of the purifier. Integrated loop on cap lets you clip the bottle to a pack strap with an accessory carabiner, sold separately. Remove the purifier cartridge to use the Katadyn MyBottle as a standard water bottle when purification isn't required.