The Sakura IDenti-Pen is a multi-purpose permanent marker. You can use this pen on paper/board products and non-porous surfaces such as metal, glass, tools, test tubes, plastics, CD labelling, wood and photographs. · There are 3 black identi-pens in this set · One end is for details with an extra fine plastic point, line width: 0.4mm · Other end is for broader lines with a tough finer point for heavy use, line width 1.0mm · Xylene free - Low odour · Waterproof · Alcohol based cleaners will remove ink from non-porous surfaces · Writes on most non-porous surfaces, such as leather, metal, wood, glass, CD, plastic and photographs