Magnetic holder with ball

This magnetic holder uses a ball which is meant to work with this locking ball and socket system:
https://www.thingiverse.com/thing:824711

Four magnets are used, two on each side. They are each either 20mm x 10mm x 4mm or
20mm x 10mm x 5mm neodymium N50 magnets bought from eBay. Search for "20 x 10 x 4mm neodymium magnets". Note that in one order, I received 4mm ones and in another order, I received 5mm ones, I don't know why. For that reason, you'll see that there are two sets of 3D printe