What can I do with an old Harbeth M30 midrange driver

I have an old Harbeth M30 driver sitting around the house. It came from my old M30. I thought there was something wrong with it so I replaced the driver. Upon further inspection, I can't seem to find any perforation with the driver and the driver looked okay.

So, I now have this extra driver. What cool things can I use it for? Can it be resold for someone to figure out if there is anything actually wrong with it (if any)? I need ideas.