Built for jobsites, Avery UltraDuty 1mm bullet tip markers are perfect for bins, metal, wood, concrete, corrugate and moreDurable polyester tips can write on abrasive, wet, dusty and oily surfaces without getting cloggedDesigned to be resistant to water, abrasion and smearing, the industrial ink won't dry out when the cap is left off for up to 72 hoursEach cap has a useful clip that keeps the markers secure, hooks into lanyards and prevents rollingIncludes 4 assorted industrial permanent markers (2 black markers, 1 red marker, 1 blue marker)