## Simple_3D_ring.stl

The file `Simple_3D_ring.stl` was created by Giacomo Alessandroni and downloaded from
https://commons.wikimedia.org/wiki/File:Simple_3D_ring.stl This file is licensed
under the Creative Commons Attribution-Share Alike 4.0 International license
(https://creativecommons.org/licenses/by-sa/4.0/).