The 780C is my favorite mechanical pencil.
A 2mm lead pencil that is as tough as nails. It wears like a wooden pencil, so it requires sharpening.
Available lead grades are:
2B, B, HB, F, 2H, H, Blue and Red. There may be non-Staedtler colors available.
That prompted me to go hunting for drafting lead pointers, another collector’s rabbit hole.
My sharpener of choice … the 1950s and 60s, Koh-I-Noor 992 lead pointer.