This is a dog tag with symbols from the Pioneer Plaque on it. It was sold through the back pages of OMNI Magazine in the 80's. The idea was that if you were ever abducted by alien visitors from another star and later released, perhaps at some old space cantina, you could find the galactic equivalent of a taxi cab driver and it would be able to take you home by following the directions on the dog tag.
I've kept this in my wallet for twenty years. You can still buy them, though the design has changed somewhat. Money back guarantee!
