This model is an adaptor to plug a 6mm flexible tube to a 20mm (3/4 inch) threading.
The 3 files are the main body of the adaptor, the insert to put inside the tube and deform it and a model of join i print in TPU.
This model makes for a good seal an i had no issue with water leaks.
It can print without support, the only special parameter i used is a few percent of over-extrusion to insure weathertightness.
Please remember that the flow through a 6mm tube is very limited.
If you prefer to use 10mm tubes you can look here: https://makerworld.com/fr/models/69574#profileId-73910