According to Moholy-Nagy, the lighting device is supposed to demonstrate both the play of light and the manifestations of movement. The model consists of a cubelike body or box with a circular opening (stage opening) at its front side. On the back of the panel, mounted around the opening are a number of yellow, green, blue, red, and whitetoned electric bulbs. Located inside the body, parallel to its front side, is a second panel; this panel too, bears a circular opening about which are mounted electric lightbulbs of different colors. In accordance with a predetermined plan, individual bulbs glow at different points. They illuminate a continually moving mechanism built of partly translucent, partly transparent, and partly fretted materials, in order to cause the best possible play of shadow formations on the back wall of the closed box. The mechanism is supported by a circular platform on which a threepart mechanism is built.