This model tests the ability of FUD to print freely moving shafts. The spacings (marked on each tab) range from 0.04mm to 0.15mm. The holes have shapes as seen in the previous model. Again each shaft has a diameter of 5mm. So the diameters of the holes range from 5.08 to 5.30mm. The bottom caps are spaced from 0.04 to 0.15 mm from the bottom of the tube. Each shaft has a tab to make it easy to turn (or not) and is marked with it's spacing. Thus the piece can be broken apart and you'll still know which tube is which.