Work through the toughest conditions with these Marks A Lot UltraDuty Permanent Markers. Designed for moments when traditional permanent markers aren't strong enough, industrial-grade markers are ideal for workshops, warehouses and construction sites. They work on metal pipes. Industrial markers are also excellent for writing on plastic bins, wood pallets and concrete walls. Sturdy tip also writes clearly on wet, dusty, oily and abrasive surfaces without clogging. Flat and angled, 0.5mm chisel tip also allows varying line widths so that you can go from thin to bold on the spot. Great as outdoor permanent markers, the specially engineered, black marker ink is also resistant to water, abrasion and smearing while still remaining bold and visible. Useful, built-in clip keeps the marker from rolling off surfaces and offers a way to loop into lanyards for extra security.