I designed this to affix my dogs poo bags to the handle of her leash.

It can be used for many attachment needs.

Recommended settings:
0.2mm layer height (I like to set the threaded section to print at 0.1mm)

2-4 shells

25% infill

UPDATED to R1:

The original version had a fillet at the top and bottom of the threaded latch.
I have printed this design many times with no issues, but realized that the bottom fillet could encounter printing issues when up-scaled. 
The R1 update has a chamfer that will be easier to print at any scale and also increases bed adhesion.