This is a diffuser for an Emisar D4SV2 flashlight.

I printed this at 0.2mm layer height, 2 perimeters, and 100% infill. 

You probably want to turn off “Ensure vertical shell thickness” if you're using Prusaslicer since the overhang on the part that stops the flashlight from going too far in likes to generate infill that messes with the infill pattern.