A simple but great infographic on hydropacks. Inventions like these can save millions of lives. http://s3files.core77.com/blog/images/2013/03/hydropack_inforgraphic_900.png
A simple but great infographic on hydropacks. Inventions like these can save millions of lives. http://s3files.core77.com/blog/images/2013/03/hydropack_inforgraphic_900.png