SteriPEN harnesses the brilliant power of ultraviolet light to make water safe to drink. SteriPEN products are a great choice for campers, hikers, travelers or as part of your first aid and emergency preparation kits. Extensive testing has proven SteriPEN to be safe and effective, eliminating over 99.9% of bacteria, viruses and protozoa that cause water-borne illness. In order for the ultraviolet light to effectively disinfect your drinking water, any particulate, sediment or turbidity must be removed from the water. SteriPEN also offers different filter options for use in cases where removing debris or particulate is needed, so that you can get the most from your SteriPEN.