A 1 mm thick, .5 in wide flat disc with red wire around it
It has black and grey metal plates in the middle of it, which the red wire is attached to at 2 ends. I found this in my Go Army wrist flash drive. It was about 3.5 inches away from the flash drive. It's NOT connected to anything.
Some say it's an antenna, some say it's a battery, and others say it's a motor. NO MOVING PARTS.