http://www.mcnett.com/Camping/index.html<br><br>You may be interested in another product that has been widely used by backpackers (esp ultralighters) for the last couple of years. Aquamira -iIt uses activated cholorine dioxide which is the product used by many civic water treatment plants. (Pure chlorine is not used as much as it was years ago.) The small downside to the product is that you have to mix the two chemicals -wait several minutes and then add to your water then wait several more minutes for the mixture to kill the baddies. It works BETTER than chorine tablets iodine drops or bleach because it can kill even cryptosporidium. When used in conjunction with a physical pre-filter to screen out the debris and sediment it is an effective water treatment. Now you can also get a 650 ml water bottle with an integral carbon filter to remove the iodine taste as well for the best of all worlds.