There are actually two mallets in there. They are for adjusting the planes and setting the wedges. To increase the cut, you tap on the blade and then the wedge. To retract the blade (decrease the cut) you tap on the heel of the body and then the wedge. The large plane in the new sets has a striking pin on the top of the front of the plane body. Striking it will also retract the blade.
The early bird gets the worm but its the second mouse that gets the cheese.