Gear Cube Extreme
Invented by Oskar van Deventer, purchased from Mefferts, 2011.
(plastic, 2.3 inches)
A harder to solve version of the
where the edge pieces along the middle layer are not geared;
shipped with stickers to go in the black U's below the gears to make a more difficult puzzle that Mefferts calls the
"Gear Cube Extreme".
Six turns bring the puzzle back to its shape; below are some example moves.
presents a solution.