EDIT: Uploaded new v2 STL with chamfers to combat elephant's foot!
Do you have a number of different brands of wooden railway? Do you find that no matter what you do, some of them just aren't compatible? This little connector is your saviour. No more sanding, no more forcing them together with all your might (only to struggle more to pull them apart!), only this little connector to save your day.
It's been designed to take up as little space as possible and interface with all the brands I have which are:
Should print without needing to rotate in your slicer at all.
The author marked this model as their own original creation.