This is a joint protector for pool cue, with both shaft-side and butt-side elements. I've uploaded three versions: radial pin; 3/8x10 pin; and 5/16x18 pin. Prints without supports. TPU works nicely for this purpose. Should work with nozzle diameters up to 0.6mm.

I've updated the STL files to work with Cura. Please make sure you are using those with "v2" in the filename.