I have one. Everyone said the switches go out but after six months, it was still going strong. I got bored one day and replaced it anyway with a on/off button. I just have to watch the light and make sure I haven't bumped it on because it's a little larger than the original. I couldn't hear it with my headphones on, so I replaced the speaker with a vibrating motor from a cheap shaver. Not much depth, but works for what I can afford. I bought a second for a backup and modified it too.