If you have a rechargeable LED light that plugs into a US wall socket, this will clip it to a ring inside a tent or some other place that needs light.
Print away. My copy got bitten by the skeinforge no-infill bug, so to make it strong enough I filled the space between the insider and outside ring with glue. Someone smarter will make the infill happen properly. Also, if you want a solid ring that you can just clip a carabiner to, delete the tiny little angled block.
And the module for carving out the plug holes has a parameter for tightness of fit. You can adjust this for your machine.
Finally, please don't make derivatives intended to incorporate conductors.