Out of the box, it is very stiff, you can probably do as many as 3-4 solves before your fingers get tired. After a few solves, I noticed one pin tends to stick to the other side instead of staying on where I push it, took the clock apart just to see one of the magnetic ring attached to one side of the pin fell out (closer inspect I see no glue residue, they forget to glue it in place) so it only has 1 side left with magnet and therefore always attract to that side. It is fixable, but no one buys a puzzle and expect to do part of the job the manufacturer left behind, so that is a big down on quality control. I wouldn’t go through the refund since the problem is fixable myself. However, I do wanna write this to let people know the potential issue you might encounter.