Tombow Art Dual Brush Pens are ideal for many types of arts and crafts. These innovative Dual Brush Pens have two tips - one is a flexible brush for thicker lines, and the other is a fine tip for more accurate details. You can use these pens just like watercolours, as they blend effortlessly! The pack includes six grey colours, which can be mixed together. The pens are completely safe to use, as the water-based ink is acid-free, odourless and non-toxic. . Pack of 6 . 2 tips: flexible and fine . Water based ink . Colours can be mixed together . Non-bleed. Water soluble. Acid-free, odourless & non-toxic. Primary colours - Black (N15), Cool Grey 10 (N45), Cool Grey 5 (N65), Warm Grey 2 (N79) and Warm Grey 1 (N89) and Blender (N000). Approx. Dimensions (mm) H 225 W 100