Tombow Dual Brush Pens feature two tips on each pen - flexible brush and fine tip in one. The ultra fine nylon tip creates clean, crisp lines for sketching and detail work. The flexible nylon brush creates fine, medium and bold strokes simply by changing the pressure applied. The high quality resilient nylon tips will hold their shape stroke after stroke to create consistent lines for borders, graphics, writing, and drawings. Each pen is available in a variety of inks that have beautiful, brilliant, acid-free colours. They are non-bleeding, odourless, non-toxic and waterbased.