A small 25mm magnetic pin or paperholder.
Easy printable, takes about 6 minutes on a bambu lab P1P, but won't take much longer on any other.
You have to pause the printer at the end of the last layer, before closing the print.
At this moment you can insert the 3x4x8mm magnets.
Watch the pollarity (north/south) of the magnets.
I admid, it is a little finnicky inserting the magnets, but when printed and done, they give a very satisfying click, when switched over.
The author marked this model as their own original creation.