Weighing in at only 2.6 ounces, Freedom is the world’s smallest, lightest UV water purifier. It is compact, lightweight and easy to use. Perfect for travel, the SteriPEN Freedom is designed to be carried easily in a shirt pocket or purse and comfortably used in even fine restaurants. Freedom treats 40 half liters of water on one charge. Water is safe to drink in just 48 seconds. So easy to use, just remove cap, place Freedom’s UV lamp in water and stir. The built in water sensor controls the illumination of the lamp and when the timed treatment is complete, the lamp turns off. Proven to be safe and effective, eliminating over 99.9% of bacteria, viruses and protozoa that cause water-borne illness.