A test print tool to determine how close the designed hole sizes are to the 3D printed sizes. The holes are 1.0mm diameter to 8.9mm diameter in 0.1mm increments.
This was derived from a similar design that I cannot seem to find again! If I could, I'd give credit to the original designer. It was a .stl file that I took into SolidWorks and cut off some useless areas on the edges and rounded the corners -- it had numbered rows and also some excessive material on the sloping edge that I chopped off, and was unnecessarily 5mm thick -- I cut it down to 3mm.
Print it and see what size holes you get. If you can't tune your printer or slicer to make the holes close enough to the same as designed to suit your needs/tolerances, you can use this print to determine what size to design holes in order to have them come out the size you want.