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!