It's not a precise nor detailed model. It has simply 4 parts to show you the basic principle of a Janney coupler.
Print in the position I posted. It's basically support-free if you print it small.
Will need to add some support with the arm part when the holes were bigger.
*it's 50% scaled in the video.
There is also a STEP file included for you to have fun with it.
https://youtu.be/ooe-gqpIfbU