Feel free to use it in your own designs if you need something like this. For flasks, piggy-banks or anything else. I used it myself for a base for a desklamp and it works great.(https://www.thingiverse.com/thing:3383610).
The screw thread is rather coarse, but therefore easy printable and well scalable. The mitered top of the plug and opening ensure that it can be tightened securely.
Happy designing :)