So, how it comes. You don't know what is a water purifier. It is a small item that you can carry in you pocket. it could help to drink contaminated water on a journey where water is bad. It was my best friend when I crossed East Africa following the Nile river partly or drinking hot water, nasty and smelly in stations. It was like drinking tea, when the temperature had cool down a bit in the late afternoon beginning of the evening. This water looked very refreshing. I used my purifier to drink it. Perhaps, as a traveller, we are not so use to that kind of water. Perhaps, local people are. perhaps, not! It helped me to drink water from the Nile or the stations as I could not boil water. Couples of weeks later. I discovered water purifier tablets turned to powder because of the sunny side of the Sahara and my initial filter was full with moulds. I cam to use the water straw this time, which the real 2 oz pocket water purifier described in project waer, which is a non stop flights with microlights during 72 hours over inundated regions to people at risk of flood. This marshall plan would reduce the importance of deathtolls in the aftermath of the water hazard. No stomach cramps, no pains, no fever...while waiting for proper secondary water sources. Why do you think the armies of the world used it and also, tourists on remote places on Earth, where it is unsafe to drink. Of course, the best flood and safety plan would be to have these items before the flood predicted arrival time. It is only complementing adaptation strategies and water mitigations on the water sources. It is not replacing traditional means. But we have to recognize that in case of a water truck disability to provide fresh water when needed the most, a non stop flight of a microlight full with pocket water purifiers could help to drink safely water. One would just have to pick them from the water. Like,if you one when you go fishing, you use a fishing net or a boat to catch the fishes.