I believe it is a fruit quality tester... here you see it being used on an Orange.
The black thingy on top is forcefully thrust into the fruit, i.e. impaled upon it, and the meter will give a quality reading.
Don't buy the fruit if it's below 50 FruityHertz.
If you ever go to the supermarket and see large holes in the fruits, then you know someone has been testing the fruit there.
On this particular orange, someone painted a XYZ coordinate system, probably they didn't know which way was up so they needed some help. You must always orient the fruit tester correctly, or the readings will be off.
I'm sure Dave will be happy to receive it from you, and after the teardown will always enjoy better fruit.