SureFire U2 Ultra High Intensity Variable Output LED Flashlight 100 Lumens of High Output for 2 Hours; 2 Lumens of Low Output for 175 Hours Virtually indestructible LED emitter regulated to maximize output and runtime Six output levelshighest for maximum light, lowest for longest runtime Tactical high beam is 5 times as intense as 2 D-cell flashlight Measures 6 inches long and weighs 5.7 ounces; lifetime warranty