Features & Benefits: Clog-resistant marker tip; Writes through dusty, wet and oily surfaces; Durable marker tip for writing on concrete, OSB and rough surfaces; Built-in hard hat storage clip; Black, Red, Blue and Green in color; Inkzall, 4 Pack, Fine Point, Colored Marker, Feature ClogResistant Tips & Ability To Write Through Dusty, Wet & Oily Surfaces,Durable Marker Tips Are Designed For Writing On Rough Surfaces Such As OSB,Cinderblock & Concrete, Ink Dries Quickly To.