NovaTac Storm LED Flashlight 3 Pre-set brightness levels for maximum versatility (0.3, 30 or 120 Max Lumens) Disorienting strobe and momentary maximum mode can be used as safety/signal feature Flat Button prevents accidental turn-on Powered by (1) CR123 battery (included) Runtimes: 120 lumens/30 min., 30 lumens/4 hrs., 0.3 lumens /240 hrs. Measures 3.3 inches long by 1 inch wide and weighs a mere 3.1 oz.