9.8 cm x 9.8 cm x 9.8 cm / 3.9 in x 3.9 in x 3.9 in
After his Gear Pyraminx, designer Timur Evbatryov came up with another design of a tetrahedron with gears. In this case the cuts were placed in a different depth which made the small triangle in the center of each face visible. This also changed the number of teeth for the edge and corner pieces.
To fully restore the original position, you have to repeat one move 24 times, that is, the corner has to be turned around 28 times. This puzzle allows a special move were two opposing edges are moved the same time.