I need some knowledge from someone who knows what this is. I just bought an Old Garrett Groundhog in mint condition. In the bottom of the box, when I got home, was this handheld metal detector. It is from the Maytronics Corporation. It is called the Pocket Prospector Metal Detector. I did a Google search, and I can't find a thing on it other than the patent for it expired in 1976, so it is pretty old. I have no instructions, etc. Seems to work perfectly, but difficult to say when you don't know what it is. Anyone ever seen one?? Know how to use it?? HELP!