This is a ruler used to correctly scale your boardgame miniatures.
One side lists a normal scale in millimeters and the other the 'height' of the figure in feet. One side lists the height on a 28mm scale and the other on a 34mm scale. The former is the most common standard for minis, but I prefer the latter for better and more visible detail, especially on FDM machines.
Load the file into your slicer and place it inside or next to your model, then rescale your model so that the top of the head touches the desired height on the ruler.
The reason I made this model is that I sometimes have no frame of reference for mini scale in my slicer. Especially if a 3dmodel has, for example, a sword raised above its head, you can no longer trust the z-axis scale measurement listed in the slicer. This ruler provides a quick and easy way to scale all your Goblins to 3'6" feet-to-eyes regardless of their weird poses.
Update:
V2 now includes base areas from tiny to gargantuan, as well as the correct amount of quotation marks to indicate feet ( ' instead of " ).