This traditional superior chalk is 95% pure calcium carbonate and is free of foreign materials that work their way into the board surface causing scratching, streaking and pitting. Erases cleanly with no ghosting. Extruded chalk is stronger, reducing breakage. 12 pieces per cardboard box. Made by Prang in France. Assorted Colors: 2 each of red, yellow, green, blue, and orange CP certified non-toxic Size: round stick 3 1/4" x 3/8"