This box contains five 11mm pieces of chalk in four unique colors:
Purple (x2) – Highly visible, very good erasing
Blue (x1) – Highly visible, good erasing
Luminous Purple (x1) – Visible, excellent erasing
Luminous Blue (x1) – Visible, excellent erasing
This chalk can be used for marking the Bible and Science and Health with Key to the Scriptures in order to read and study the Christian Science Quarterly Bible Lesson. Each piece has a light coating, making them usable with or without the black plastic 11mm chalk holder.