Gridfinity Pen Holder 2x4 4U

I remixed @dissendat_154107 model of a gridfinity pen holder for 4 pens for a more compatible stackable version for my fountain pens. Original measures 2x4 3U high. I adjustet heigth to 4U Can hold up to 4 pens. Now for bigger fountain pens like Lamy or Jinhao or Faber Castell Hexo Perhaps a 5U Version for the bigger Jinhao or Mont Blanc pens in the future.