Customizable Grommits (and plugs)

Sorry, but this thing isn't about British claymation. ;)

Rather, this thing is for creating rubber grommits commonly to seal pipes or wires passing through a sealed container. You can also do a plug which is just a grommit with no hole.

It is also a test of my "auto units" library, so for many values you can type in most anything you want and it should "do the right thing".

This thing also lives on my projects blog, here:
https://theheadlesssourceman.wordpress.com/2017/07/13/customizable-grommits-and-plugs/