The clip is 0.4" at the throat and 0.5" at the bottom.
This hook is designed to clamp snugly on the top of the boards of standard wood fences (US). Originally designed to hang Christmas string lights, but I made it beefy enough so it can be used to hang other things.
Since this is for outdoor use, I recommend to print in ASA for UV resistance.
Use 3 to 5 perimeter shells depending on use. For Christmas string lights, 3 shells should be sufficient. 20 to 30% grid infill recommended.
I used Fillamentum ASA.