The Milwaukee Hand Tools INKZALL™ Fine Point 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 stylus end can be used on iPads, iPhones, tablets and touch phones. 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.