Gear Cube Cube. Three 3x3 cubes are very similar to the original: the Gear Cube Extreme, the Gear Cube Ultimate, and the Even Less Gears Cube. Gear Cube Extreme: Unlike the original Gear Cube with 12 total gears, the Gear Cube Extreme (also known as the Anisotropic Cube) has only eight gears. The top and bottom rows remain gear cogs, whereas the middle layer edge cogs have been removed. Taking away the middle layer cogs and replacing them with standard edges allows for different movement between rows. Due to the added straight edges, the cube can now make 90° turns on two
Folded cube graph as many vertices, by identifying together (or contracting) every opposite pair of vertices. An order-"k" folded cube graph is "k"-regular with 2 vertices and 2"k" edges. The chromatic number of the order-"k" folded cube graph is two when "k" is even (that is, in this case, the graph is bipartite) and four when "k" is odd. The odd girth of a folded cube of odd order is "k", so for odd "k" greater than three the folded cube graphs provide a class of triangle-free graphs with chromatic number four and arbitrarily large odd girth. As a distance-regular graph with odd