The LanLan Gear Rhombic Dodecahedron is an exotic-looking and exotic-sounding 12-sided gear puzzle. The intricate gears rotate smoothly right out of the box. The LanLan Gear Rhombic Dodecahedron really is a toughy with interlocking teeth and gears designed to throw you off at every turn. You will be stuck on this one for a while.