When you're out hiking Paths or biking the road make sure you're carrying the Katadyn MyBottle Microfilter Bottle to stay adequately hydrated. By drinking through the mouthpiece/straw H2O gets pulled through a three-stage microfilter that filters out protozoa and bacteria. A layer of carbon removes harmful chemicals and any off-flavors that may be present. Made of BPA-free polyethylene, the Katadyn MyBottle Microfilter Bottle is Great for camping, hiking, travel, and for everyday use.