A small drawback is, as already noted in some reviews, the thread of red plastic but that did not bother me.
The other processing seems to be very solid if not outstanding and with the supplied air it writes also quite pleasant.
What the printing mechanism is so cheap to come off or is processed in such a pen, in my opinion, but less important. Pressing the Kugeschreibers is really unsatisfactory. Far too soft, the spring in the mechanism so that when you press one thinks would have just a 99ct Kulli in hand. Also, the push-button itself has quite a lot of game, what are the * forth just press a satisfactory and precise * clack.
All in all, the rotring rapid PRO but a good pen, the flat also has its weaknesses!
Who can ignore a plastic thread and the defects in the push button will be very pleased with the scribbler with security.