The Mission White Liquid Chalk Markers are fantastic for use on all types of markerboard. These pens provide a great alternative to chalk and traditional dry wipe markers. The liquid chalk markers are non toxic, water based, odourless and can be simply wiped away. Each pack contains four white markers and every marker is fitted with a reversible nib that can be set to either bullet or chisel. The pens can be used to write on all non porous surfaces.