Summary

These are three adjustable supports.
I designed them with three height ranges.
82 to 122mm
112 to 182mm
142 to 242mm
Top and bottom diameters 40mm.

Good for holding anything you may be working on at a certain height.
I have one supporting the back end of a heavy graphics card in a gaming computer.
Those cards tend to sag from their weight, putting stress on the card.
Problem solved.