The Adventurer Opti packs all the speed, power, and effectiveness of SteriPEN purification into one compact, portable package. At half the size of classic SteriPEN models, the Adventurer Opti is so lightweight, you'll hardly know you're carrying it. Purifies a half-liter of water in just 48 seconds! Comes with a new optical sensor that doubles as a conventional LED flashlight. Custom-fit neoprene pouch included. Operates on two CR123 batteries (included). Battery life: 100 treatments, non-rechargeable (disposable); 40-50 treatments, rechargeable. UV Lamp Life: 8,000 treatments. Weight: 3.6 oz. with batteries. Height: 6.1". Volume: 4.75 cu. in.