America s favorite dustless chalk. Makes clean distinct marks on chalkboards for maximum visibility and contrast, erases cleanly with no ghosting. This superior chalk is 95% calcium carbonate, free of foreign materials that work their way into the board surface causing scratching, streaking and pitting. Round stick is 3-1/4 x 3/8 fits many chalk chucks. Certified non-toxic. Your choice of white or yellow. 12 sticks per box.