The Katadyn MyBottle Microfilter is a multi-purpose filtration system. It meets EPA guidelines for removal of bacteria and protozoan cyst (like Giardia). This economical microfilter system is easy to operate, reliable and the internal carbon filter also reduces chemicals and makes water taste better. As always, each MyBottle includes a drinking straw to use as your everyday bottle if the source water is already safe to drink. Perfect for hiking, biking, paddling or fishing. No hoses, no fuss. (the MyBottle Microfilter can be easily upgraded to a Purifier by adding the Katadyn purification cartridge - sold separately).