Six sides with box joints that can go together to make a cube with each of the digits; 1- 6, the names of the numbers spelled, and groups of shapes with the same number of sides as the number. The small elliptical shape a few millimeters from each side is a signal for a filament color change. You can watch the printer head and pause after it quits going to the ellipse to avoid pausing too early. Thanks to the Brookfield Public Library in Illinois for their great 3D printing program, 3DP Club and wonderful staff.