I usually work with headphones on and the entrance to my cab is behind me. As a result, I either have to look over my shoulder a lot when I suspect a colleague has entered my room, or they just scare me to death. This mirror fixed that problem. It's a pretty decent size; on all sides it is slightly larger than a dollar bill. The hand holding the mirror is VERY strong, so it's a bit difficult to get it at a good angle, but it's a good problem. The clip part is very versatile, you can attach it to a cabinet or some computer monitor parts as long as your monitor is the same thickness.