Has several brightness settings so you can choose the most beneficial for your setting. Comes fully charged and it lasted about 6-8 hours. The only complaint I have is that no matter how long I leave it out to recharge the power bar has only shown it's about 2/3 charged. I thought it might be a fluke but I ordered a second one for my son and his does the same thing. Fully charged out of the box, never fully charges after the first use. Even with a lesser charge it lasts 4-5 hours on full bright so I'm only deducting one star.