Hydro-Photon SteriPEN Emergency NA Imported Compact handheld UV water purifier designed specifically for emergencies Destroys more than 99.9 percent of harmful microorganisms, including Giardia Safe and effective without altering taste, pH, or other properties of water Purifies 200 half-liter servings of water per 4 AA lithium batteries (not included) Measures 1.5 x 7.6 x 1.5 inches (W x H x D); weighs 5.7 ounces