The ink pen itself I suppose, because of the beautiful typeface, for exams.
Currently I have two exams to the clerk behind me, the first cartridge is still in there and did not have to be replaced. Due to the "color hunger" how to read here often, always a spare cartridge is ready, because nothing would be worse than not being able to continue to write in the exam.
To date, I can neither confirm nor revise color hunger ... I will supply later on occasion.
Because of the shape, weight and grip, I find the ink pen very comfortable to hold and that I can also in an increased pace still a passable writing on the paper spells (with a pen is it messy and illegible).
In my opinion, a beautiful writing instrument, I do not want to miss it! =)