Small magnetic fidget toy I designed from fusion and printed on Ender 3 s1.  There are two files, the first you would print and then pop the magnets in place, the second encapsulates the magnets in the print, so you need to run a macro for a filament change on the correct layer for your settings.  

Standard quality 0.2 layer, 20% infill, printed with supports on the file with the exposed magnets so it can be popped out and magnets dropped in.  The fidgy 2 file has embedded magnets, so you'll pause the print on the correct layer, meaning no supports are needed.

These are 6mm magnets, about 1.5mm thick, that I got off amazon here: https://www.amazon.com/Neodymium-Magnets-Permanent-Strongest-Powerful/dp/B0BBWH44YT/ref=sr_1_4?crid=3OXC9CUGHRSDS&keywords=1%2F4+by+1%2F16+magnet&qid=1692474536&sprefix=1%2F4+by+1%2F16+magnet%2Caps%2C145&sr=8-4

They say ¼ by 1/16 inch, but I measured them in mm and they work out at 6mm by 1.5mm.