In contrast to other key chains, which I found, the outer shape of this key chain is adapted to the contour of the font, and so the size changes dynamically. The font can be made lower than the edge, so that the letters are somewhat protected. In addition, the filament color can be changed for the last one or two layers of the font. If you then continue printing with the basic color, only the font gets this color, not the frame.

To customize your own key chain:

Install OpenSCAD on your PC, download the file, and open it. Ensure that the “hide customizer” under windows is not marked. You can use all installed Fonts that were displayed under “help - fontlist”.