This is a matchbook flashlight that I made with instructions from the book "Show Off: How To do Absolutely Everything One Step at a Time" by Sarah Hines-Stephens and Bethany Mann. Simple, but fun. ;) Would be good for a group project for Girl or Boy Scouts, etc. It takes two LEDs that I cannibalized from a string of on-sale christmas lights, one matchbook cover, and one watch battery. The watch battery is the expensive part.