Pocket Travel Well is designed to meet specific requirements for the treatment of water in emergency and survival conditions. Using the proven filtration and sterilization system of Pre-Mac's highly successful PWP, the Travel Well Pocket will provide safe drinking from contaminated sources. Size and weight have been kept to a minimum for inclusion in emergency packs. Pocket Travel Well is convenient to use and will not block-up due to its high filtration capability and built-in pump. The rated capacity of Pocket Travel Well is 50 liters, at which point it should be discarded. The effectiveness of Pocket Travel Well has been proven in tests carried out by the London School of Hygiene and Tropical Medicine. In their tests, total elimination of the bacteria Escherichia coli at 108.4 per liter was recorded. Reductions of Poliovirus in excess of 99.9%, with a holding time of 2 minutes, were also recorded. This effectiveness is maintained throughout the stated treatment capacity of 50 liters. Shipping and Handling costs added. When you are finished shopping, please visit www.eri-online.com.