This is the venerable and excellent Ticonderoga pencil. It is great and readily available everywhere. This is the one you think of when the word Pencil enters your mind.
I love that it is available in a range of hardnesses.
1 / B - (extra soft / black)
2 / HB - (soft / hard black)
2.5 / F - (medium / fine)
3 / HF - (hard / fine)
4 / 2H - (extra hard)
Number 2 is what you can get everywhere and perhaps it is acceptable to some. I prefer a darker line and I get that with a Number 1/B.
This is a pretty great pencil and I recommend it wholeheartedly.