I had this attached to my backpack for about a month. I used it at a concert to read the program in the dark, which worked out great for me. Apparently it's quite visible because my daughter saw me from the stage.
The light came to a sad end one night when I went out for a walk. When I went to turn it on, I discovered the battery back had fallen off and the battery had fallen out. Next time, I'm going to nail polish the back on.