The chalk brushes out easily, which means I must reapply the line, but that's just fine. When I'm done I can quickly wipe it off. No need to wash!
It has a little duck-billed tip.
Clover Chaco Pen Refills, are also available. They come in white, blue, pink, yellow.
I found the yellow worked well on both dark and light colors.
Tiny dotted rotating wheel at the tip.
I'm happy with it.
Addendum 12.24.17: I had a little trouble getting the yellow chalk off of black cloth, but found that with an ordinary lint brush I was able to brush it right off.