Around 4.5cm in diameter, but can be printed pretty much at almost any size (printed a ¼ mini model and it works just as fine.
It's not that useful really, but it was a good exercise to find alternative locking mechanisms to screws :/
Supports should probably used if you intend to scale up the model, otherwise it should be fine.
If anyone wants the on-shape document let me know and I'll send it over!
The author marked this model as their own original creation.