These Stanley Fatmax chisel tip permanent black markers are ideal to mark out in all-weather / environmental conditions. They have a strong durable chisel tip which reduces wear and tear even when they are used on abrasive surfaces. They are water and oil resistant. The Bi-material hand grip provides ease of use in all weather conditions as well as when wearing gloves. They can be used to mark tools and equipment and for marking copper roofing material, gas pipe, black pipe, wood, metal, concrete, coating roof, pipe, and welding. Pack of 2