It comes with two double A batteries and the light is 100% bright enough to work in the complete dark. The first mode (big light on the body) has a decent spread and will light up a big enough section for you to work on without needing to move it. The narrower top beam is dimmer and good for pointing at a specific spot but definitely won't be something you want to use as a substitute for a better torch style flash light but will do in a pinch.
it has great magnets on the bottom that will easily stick to metal and not move at all, of course you can bump into it and move it but you'll need to pull it off it probably won't just fall from a bump. You can also adjust it to different angles and set it down and it'll balance on itself without needing to prop it on anything.
The brightness isn't anything to brag about but for the price you can't ask for anything more. The batteries it came with so far have lasted 4 hours with no change in brightness, will update when they start to die out. Dropped it a few times and it's survived, feels durable but not too heavy. Enough heft to feel comfortable knowing you can be rough with it (to a point) and not break anything. Sorry for the video, it's hard to show how bright it is when my phone camera kept adjusting the exposure in complete darkness.