Calibration Cube Dice

This is a Calibration Cube with 20mm x 20mm.
I was doing a lot of tests with the famous "XYZ 20mm Calibration Cube" and i have no use to them so i decided to draw/model a dice and other forms.
1 - calibration cube dice 20mm x 20mm
2 - calibration cube clean 20mm x 20mm
3 - calibration cube XYZ 20mm x 20mm
4 - calibration cube MMM 20mm x 20mm
5 - calibration cube structure 21mm x 21mm
6 - calibration cube design 21mm x 21mm
Feel free to use them!