Same tips as included with pencils.

These tips last for a long time… but look at the news. Societal collapse could happen at any moment. Why not stock up?

These use a special graphite-metal alloy and break down very slowly: I've yet to dull one more than I want to keep using it (!), but I've heard suggested from my partner company who makes these that one is expected to last as long as 10 or so full #2 pencils (that's full pencils, not sharpenings).

These tips are capable of shading and leave a dark mark I find indistinguishable from a quality, firm graphite pencil. They erase cleanly, don't leave dust. For lefties like me... they don't smudge!

When the tips eventually wear down (or for people with particular tastes), these are quickly reshapable to taste with a small piece of extremely fine sandpaper (included).

This basic tip style is starting to become more widely available. Order from elsewhere if you prefer; I've just found one supplier whose product I particularly like (darker lines than most).