Rack Stopper
This is a block that goes into a wood working vise to prevent the vise jaw from racking when only clamping on one side. Has 7 different thicknesses from .25" to 1.75" in .25" increments.
It has convenient hole for hanging from nail, screw, or peg.
I have not printed this yet. You will probably want to print this pretty solidly since it will be under quite a bit of pressure