This is a special part used by crafters, it is a bead with a square base.
My goal here was to demonstrate how to do some simple geometries in Tinkercad.
Here is a link to the Tinkercad model: https://www.tinkercad.com/things/1MbADUkl0LW-bead-with-square-base
The author marked this model as their own original creation.