This model allows for an easy to see test of the detail acuity of your 3d printer. From this you can expect a 20mm (more or less) star. This model also has some rounded pieces, so if you were concerned with your printer about rounded edges, here you are. DETAIL TEST ADDITIONALLY___ This is the FIRST publication by SouthGeometricWorksYou need to prepare the design in the prepare window, of the downloadable maker-bot software.