The ultralight, super soft and flexible water flask with integrated filter weighs only 59 grams (2 ounces) and fits in (almost) every pant or shirt pocket. Such convenience makes the BeFree your ideal trail companion for longer adventures or trail runs. Using it couldn’t be more uncomplicated: Simply fill the flask and tighten down the mouthpiece. While you drink, water feeds through a 0.1 micron hollow fiber filter that reliably filters microorganisms such as protozoa and bacteria. The ingenious system is composed of a tough BPA- and PVC-free 0.6L Hydrapak SoftFlask™ with a 0.1 micron hollow fiber filter that can treat up to 1,000 liters of water. The flask is easily filled with its wide 42mm opening. Free Flow Channels™ ensure fast water flow when drinking. Plus, the hollow fiber filter can be cleaned simply by shaking or swishing in water -- without the need for backflushing. The nozzle also has a protective cap to keep it clean along the way. Other notable advantages of the BeFree: It is the only hollow fiber filter on the market today for which replacements are available. In addition, the nozzle cap can be replaced.