This is a nozzle size indicator to keep track of the current nozzle size. It was sized to fit on an Ultimaker front panel, but might work for others (X = 30 mm; Y = 40 mm). It has tiles for the following nozzle size: .25, .4, .6, & .8 (Each tile has 2 sides with a different size on each.)
I will try to add an SCAD in the near future to make the size list customizable.
The text is .5 mm deep (from the surface). If you want to change the filament to color the text, then you have to change filament color at .5 mm Z height and back to the original color at 1.5 mm Z height. (Can print all 3 pieces on the same build plate as they are saved in the STL.)
The holder has a lip when printed on it's back. Haven't tried printing without support, but a support roof and floor will make this small support strip come out easily. (Support settings I used for easy removal - Layer Height - 0.1 mm; Enable Support Interface; Support Z Distance - 0.2 mm)