Print the main-part with the round part on surface - need support on Printbed only
The holder for the back side doesn't need support
The hole has a diameter of 52 mm
The Wall minimum is 10mm and max
Banana Plug Insert - https://amzn.to/32f8M76
Banana Plugs - https://amzn.to/3E4pm6Y
The author hasn't provided the model origin yet.