✔【High-quality materials】The professional water brush is made of high-quality plastic and fiber materials, with its own water reservoir, which will not leak; the nylon brush head has good elasticity, easy to control, and will not spray, spread or smear. ✔【Easy to use】When using, just fill the water tank with water, dip the pen into the brush head, dip the paint, and just squeeze the pen holder to easily control the flow of water or ink. (Note: When the water brush pen is filled, the water volume should be less than 2/3 of the total capacity) ✔【Easy to clean】After use, just rinse them with tap water and let them air dry. When not in use, please use a protective cap to protect the pen tip to avoid unnecessary damage and prolong its service life. ✔【Multiple uses】very suitable for watercolor painting, oil painting, writing, etc.; it can easily handle most writing or painting work. You can use it with water-soluble color lead and solid watercolor paints. ✔【You will get】The watercolor pen set includes 6 brushes with different nibs: 3 round nibs and 3 flat nibs. The diameters of the three round tips are 3mm, 5mm and 5mm respectively; the diameters of the three flat tips are 3mm, 4mm and 5mm respectively.