This coupler is designed for hands-free RV freshwater holding tank fill-ups. Especially useful for de-winterizing your RV.
The coupler is designed for the hose that I use. If I keep screwing the coupler onto the hose, it ends up passing the threads and allows the couple to spin freely. This way you can attach the coupler, but still keep the hose kink-free.
I'm not sure how universal this coupler is since I've only owned one travel trailer. I designed it for use with my Safari Condo R1723 (https://safaricondo.com/en/caravanes-alto-serie-r-1723/).
Please leave a comment if you're having troubles with the design. I will try to make edits if there are issues. Also, if you have a better name for this thing, leave a comment. I don't know if the name is really useful, but probably better than "water thingy."
Thank you lowenski (https://www.thingiverse.com/lowenski/about) for sharing your model for a hose fitting. I used it for the threads on my coupler.
I designed this particular model using only Tinkercad. While simplistic compared to my other go-to solution, Blender, it is really quite flexible and easy to use!