The file '2.5″ Hitch Tube Receiver Cap W/ Radius On Edges 3D Printer Model' is (stl) file type, size is 1.5KB.
This is a remix for "GMC HITCH RECEIVER CAP" by @toddbmobile
original part: https://www.thingiverse.com/thing:4745306
I have round edges on my tube, so it needed a bit of modification.