I checked a few times - Can't see them anywhere.
Because the 12.1" screen is large the friction fit isn't that great as the X only makes contact at the edge and it makes it bend a fair amount, so the center is not close to the back of the screen - loosening it, it doesnt hold it at all. (because of the depth of the screen vs the size). With an additional nut on each corner that might help it though.