What kind of board chalk is this?

[daveyp225]

In the following MIT video, some kind of thick chalk (not sidewalk, already tried it) is used in the lecture:

http://ocw.mit.edu/courses/mathemat...us-fall-2006/video-lectures/lecture-2-limits/

It looks like great chalk. Or what chalk is this easy to write with?

 

[Pythagorean]

didn't look at video, but:

https://www.amazon.com/dp/B004IM79HI/?tag=pfamazon01-20

coffee shops use this kind of chalk a lot because it allows them more control when drawing pretty menus on blackboards.

 

[daveyp225]

Thanks for the suggestion. I have to erase a board probably 10 times a lecture, so wiping it down with water will not work well for me.