I haven't actually had the lights turned on (except for testing purposes yet), but they are a nice size and seem to be pretty bright. I have been looking for battery operated lights for my projects and these seem like they will work nicely as they are individual so you can use as few or as many as you want - unlike string lights that may be too long for my needs. They are easy to turn on and off by just twisting and so far, I haven't twisted them far enough to make the tops come off accidentally. They have a loop at the bottom that you can thread through to attach them, but be aware that there is a bit of twisting to turn them on so you're not going to want them to be overly stationary (e.g. you won't be able to glue the whole thing down onto something because you won't be able to twist to turn on and off).