... dust. 2,natural mineral without any chemical ingredients. 3,1pc slate pen equals 20pcs common chalk for using. Basic Information: Item No ... N.W.(KGS)Ctn Size(CM)OB-50white2400191739*39*28Features1,slate pen,the same function as traditional chalk.2,which is made ... mini blackboard,chalk board, whiteboard, writing & drawing boards,color clay,slate pen and so on. Our company takes quality as the lifeblood ...