Inkzall, 4 Pack, Black, Fine Point, Marker, Clog Resistant Marker Tip, Writes Through Dusty, Wet & Oily Surfaces, Durable Marker Tip For Writing On Concrete, Sob & Rough Surfaces, Built In Hard Hat Storage Clip, Ink Dries In Seconds, Lanyard Hole, Anti Roll Body Design, Non Toxic Ink.