INKZALL Jobsite Markers feature clog resistant tips and the ability to write through dusty, wet or oily surfaces. The durable marker tips are designed for writing on rough surfaces such as OSB, cinder block and concrete and the ink dries quickly to reduce smearing markings, without drying out quickly when the cap is left off. For added user convenience, the INKZALL markers have a built-in hard hat clip for easy storage and access. INKZALL markers confirm to Milwaukees commitment to best-in-class durability and their relentless mission to provide innovative solutions to the end user. Stays sharp, doesnt mushroom or push back under pressure.Acrylic nib ideal for rough surfaces such as OSB and concrete.Marker continues to write after 72 hours of cap off time.For use on concrete, wood, metal, plywood, OSB, plastic.Can be used on wet, oily, dusty, rusty, with debris surfaces.Quick dry time reduced smearing markings on PVC, metal surfaces.Thin body for use in restricted areas.Helmet clip can be clipped to the construction site cap, trousers, overalls.Easy open cap for one hand operation.Lanyard hole, e.g. to attach the INKZALL highlighters to the belt.