The Milwaukee Hand Tools INKZALL™ Fine Tip Marker stays sharp, doesn't mushroom or push back under pressure. It has an acrylic nib, ideal for rough surfaces such as OSB and concrete. The ink has a quick drying time, which reduces the risk of smear markings on PVC and metal surfaces. Marker continues to write after 72+ hours of cap off time. The thin body is ideal for use in restricted areas with an anti-roll design, so it won't roll off surfaces. With an easy-open cap for one-hand operation. There is also a handy helmet clip so it can be clipped to the construction site cap, trousers, overalls etc. and it also features a lanyard hole. Ideal for use on concrete, wood, metal, plywood, OSB and plastic. Can be used on wet, oily, dusty, rusty, with debris surfaces.