Move the two gears to navigate two ball bearings through the maze. Much harder than it sounds - not only do you have to keep track of the positions of both balls, moving the ball in one maze can be dependent on the position of the other.
A good quality, nicely made puzzle. Comes in a wood box.
One note - when putting the balls into the maze for the first time, make sure the marks on the outside of the gears are aligned. Otherwise, you won't be able to work the puzzle.