Near me is a Goodwill Outlet where everything is sold by the pound. In a laptop bag I found what I thought was a flash drive. It is very light, so I gambled and bought it for a few cents. The main body is a disk about the diameter of a quarter and about 3/8 of an inch thick. It is flat on one side and slightly concave on the other. There is no response at all when I plug it into a USB port on my Windows computer.
Any ideas on what this might be?