This quality Pilot 400 marker contains permanent, oil based ink, which is suitable for use on a variety of surfaces including plastic, metal, wood, card and glass. The vivid ink is long lasting with a high resistance to abrasion. The marker also has a cap off time of 24 hours, and the chisel tip writes a variable 1.0 - 4.5mm line width. This pack contains 20 markers with permanent black ink.