MARKER PEN: non-toxic,can be re-used use on any smool board rich color for choose, MARKER PEN: The liquid chalk pen, as we term it, uses its body structure to hold the ink, and with an automatic valve controls the liquid flow directly and easily. Can be refilled with ink, and the nib can be replaced,100% effective used. Has rich and bright colors, of white, red, yellow and blue,which fully meet ...