Each graphite lead refill is 120mm long and break resistant ... Though not as ubiquitous as the German brand’s mechanical chubby pencils, it’s a must-have for any technical draughtsmen ...

You might have, or can inexpensively buy, a mechanical pencil which has the feeder button on the side rather than on top, as usual. With the pencil in hand, [ptkrf] shows you the simple procedure ...