Autopoint

This pencil was invaluable for my graduate b-school exams. I used a combo .7 mm tip for numeric problems and the .9 mm tip for the essay section of the questions. The pencil is fool-proof if the correct sized lead is used and although the mechanism may seem simplistic - it works. The only way to jam this pencil is to try to force an oversized lead through a smaller diameter tip. The tips can be swapped out with different barrels and the pencil can be customized for different situations. This is the only pencil I am aware of that can be customized in that manner.