The file 'DC Barrel Jack Mount 5.5 X 2.1 25 3D Printer Model' is (STL) file type, size is 183.9KB.
How a hollow bushing connects and the holder is produced can be seen below:
https://nerd-corner.com/using-a-barrel-jack-as-a-switch/
or
https://nerd-corner.com/de/hohlbuchse-als-schalter-verwenden/
BuchsenhalterSW22.STL | 221.2KB | |
Halter25.STL | 514.1KB |