Dry-erase markers work well on whiteboards, glass and other nonporous surfaces. Low-odor, nontoxic ink wipes off easily with a dry cloth or eraser. Durable chisel tip writes in three line widths and won't "mush" or fray. The nontoxic, low-odor, certified formula makes the marker safe for use at work, at home or at school so you can communicate virtually anywhere. The ACMI certified markers conform to ASTM D 4236.