This is a frame mount for a reverse bowden tube fitting. The hole will thread an M6 fitting into it. This has the same profile as my LED light bar holder and can be mounted right next to it:
https://www.thingiverse.com/thing:3431320

Prusa

i3 MK3

No

No

0.2

15

4 perimeters and 15% infill. I laid it with the arm for the fitting sticking straight up and no supports.