Katadyn MyBottle Personal Water Purifier - ViruStat Microbial Water Purification Cartridge Easy to use. Purifies water without batteries, pumps or hoses. Removes Microorganisms and sediment from untreated water. Registered as an EPA water purification system and kills 99.9999% of bacteria, 99.99% of viruses and 99.9% of cysts like Giardia and Cryptosporidium. An excellent choice for international travel, hiking, paddling or biking. Multi functional. Includes straw for everyday use in tap water. Straw may be used instead of purification cartridge when water is treated and safe to drink. EPA registered. Proven to make water microbiologically safe to drink. * Cushioned mouth piece - Easy drinking and folds flat to prevent leaking. Removable for easy cleaning. * Virustat Cartridge - Virustat microbial water purification cartridge kills waterborne bacteria and viruses. * Cyst Filter - Removes pathogenic cysts such as Giardia and other contaminants larger than 1 micron size. * Carbon Prefilter - Removes sediment, reduces chemicals, eliminates odors and improves taste of water. * Cartridge Life Counter - Integrated mechanism indicates when to replace your filter. * Straw - Includes straw to use instead of purification cartridge if water source has been treated and is safe for drinking (like most tap water).