A side piece for the Fidget Ball with an indent sized for a single penny. Pennies are no longer in production, which I believe technically makes them collectors' items, so why not flaunt your wealth? Designed for .2mm layers, but shown here printed with BambuStudio's "adaptive layers" feature; either way works. (Also, depending on your printer's exact tolerances, a dab of glue may or may not be needed.)

(PLEASE NOTE: This is only a side piece. For the rest of the model, look here.)