The ZIG Posterman 30mm Extra Broad Tip Wet-Erase Markers feature a 30mm broad tip and are wet-erasable on most surfaces. ZIG Posterman wet-erase markers are liquid chalk markers that produce a chalk look without a chalk mess. Easily removed from non-porous surfaces with a damp cloth. Ideal for use on plastic; wood; glass; metal and a variety of other surfaces. Perfect for writing letters on signs; boards and more.