This is a parametric object generator to print tubes, rings and other cylindrical shapes. Object may be use as jewels, for printing calibration, to connect tubing...Parameters: Inner Diameter: the inside diameter. Thickness: the thickness of the shell (an object thinner than 0.6mm may not be printable). Height: the height of the object. Type: 3 types of tube ; cylindrical, toroidal (makes a torus if Height = Thickness), cylindrical with rounded ends.