Here is a link for you. The SAS, British Civil Defence and us use these for water purification. They have NATO stock numbers and probably available in US. The SWP, MWP and PWP are field tested may go into different sizes of kits if you just do not mind the taste of iodine. I also use it for diarrea treatment:))<br><br>http://www.pre-mac.com/MIL_P1.HTM<br><br>PWP achieves a zero virus count in the design time of 2 minutes - a reduction of 99.99%.<br><br><br><br><br><br>Survive and Protect