How can a GBC be called Mill Madness if it would only consist out of one mill? It cannot! Hence, meet the Watermill Module! Just like a real Watermill, this module is not powered by a motor or some kind of mechanism. Instead the GBC balls push the 12 spokes, rotating the Watermill Module! Even though the GBC balls are quite light, they can make the whole module move, how cool is that?!