Built for situations where standard permanent markers just aren't enough, Marks A Lot UltraDuty Markers are perfect for construction sites, warehouses, workshops and more. Durable, XL chisel tip also works on abrasive, dusty, wet and oily surfaces without clogging. Angled, 18mm chisel tip allows you to write lines in varying widths to switch from narrow to bold on the spot. Bold, fast-drying ink works great on plastic, wood, metal, corrugate and concrete. Specially engineered to resist water, abrasion and smearing, the heavy-duty ink makes sure that your writing will last through even the harshest of conditions. Durable ink is designed to last and won't dry out when the cap is left off for up to 72 hours. Cap also features a useful anti-roll bump to help prevent rolling.