With the Katadyn BeFree 1.0 liter Water Microfilter, you no longer have to worry about where your next drink will come from. Just fill up the 1.0L HydraPak flask and let the EZ-Clean membrane do the work. Gently squeeze the flask for instant treated water wherever you go. Maintain the EZ-Clean membrane quickly and easily for longer life and more enjoyment by simply fill the flask with water, attach the cover and shake free the debris. Or, remove the filter from the flask and swish in any lake, river or stream. And when you're ready to "hit the road, " the collapsible flask packs small to fit into tight spaces (running or pants pockets, cycling jerseys, fly vests, purses, etc.). Just smash, stash and go! Worry less and discover more with the BeFree Water Filter.