Tabletop RPG grid markers

I needed some square markers for my D&D campaign so I design these ones

As I use 1.5cm square grid I made this markers in this scale.
The holes are there to aim the square right in the grid

The source file is a FreeCad (0.17) file with a Spreadsheet to customize everything
As I did not intend to publish this, everything is in portuguese, but for you guys, I will make a simple hint:
"Largura" is Width in squares
"Altura" in this model is length in squares
"Escala" is how many millimeters per square
"Espessura" is the thickness from top view
"Pad" is the height in millimeters

One day, if my free time allow, I promise to translate and improve the source file

Feel absolutely free to translate, modify, adapt or anything you want