An interesting relic from the days before calculators became popular. It's plastic and about 6 inches long. Comes with instructions how to use it. Interesting curiosity for someone who likes math or science. A stocking stuffer for the geek who has everything! Asking $1.41 pphf. I will also throw in a free $5 gift card to the Learning Place. Check or money order also ok Let me know if you are interested. email glenlogie@gmail.com Thanks