The Katadyn Befree Microfilter Water Bottle gives you the freedom to drink anytime and anywhere. With the BeFree™ Filter, you no longer have to worry about where you next drink will come from. Just fill up the flask and let the EZ-Clean Membrane™ do the work. 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 youre ready to hit the road, the collapsible flask packs small to fit into tight spaces.