Very useful, however, the holes, which allow it to me are sometimes quick to draw parallels lines, even over several meters.
Unfortunately, the holes too big, so that you can work well only if the pencil is blunt. Usually, however, you want to use a sharp pencil, which then has too much play in the hole and the lines are inakurat. Very unfortunate.
Thanks to the hole at 0cm can this wonderful as well using a nail used as a fixed point and has so within seconds a circle.
The protractor is a nice addition, but so far have not needed him.
Unfortunately you wanted here create a universal tool, at the expense of the individual functions.
Nevertheless, I regret not buying, because the product was not so very expensive. It is still propagated a useful addition in my workshop, even if it has presented its potential.