Steripen Freedom Water Purifier Perfect for travelers visiting areas with questionable water quality, the SteriPEN Freedom is designed to be carried easily in a shirt pocket or purse Treats 40 half liters of water on one charge-Water is safe to drink in just 48 seconds Eliminating over 99.9 percent of bacteria, viruses and protozoa that cause water-borne illness Award winning - recipient of American Alpine Institute Guide's Choice Award, Men's Journal Gear of the Year and About.com Readers' Choice Fast, safe, effective and chemical-free. Doesn't alter taste, pH, or other water properties. Reusable to purify up to 8,000 liters