Hydro-Photon SteriPen Adventurer Purifier Handheld water purifier that effectively destroys viruses, bacteria, and protozoa Purifies 16 ounces (1/2 liter) of water in 48 seconds or 32 ounces in 90 seconds Employs ultraviolet (UV) light to destroy DNA of harmful microorganisms Exceeds U.S. Environmental Protection Agency guidelines for purifier testing Easy 1-button operation; weighs only 3.6 ounces; includes 2 disposable batteries