SteriPEN Classic 3 UV Water Purifier - Is all that is needed when camping, hiking, backpacking or traveling. It offers enhanced ergonomics and battery life as well as improved water resistance. An 8,000 treatment lamp delivers a lifetime of purification. Effective against: Bacteria, Protozoa, Cysts, Virus Treatment Size: 1/2 or 1 Liter Treatment time: 48 or 90 seconds UV Lamp Life: 8,000 treatments Battery: Uses (4) AA Lithium batteries [not included] Weight: 6.28oz Size: 7.6 in x 1.5 in x 1.5 in