I bought some of these ones but my personal opinion is: Needless and waste of plastic. You can fill in colour and paint by pressing the pen. The more you press the more colour comes out. These are the cheap ones and they lose hair. I hope that the “PRO-Edition” is better but I won’t buy it. I prefer normal brushes for my work and I can recommend for example Da Vinci brushes. Keep them clean and they will stay with you for a long time. Anyway – I will give them to my six year old nephew.
Comment: Ok – One day later I found this one and as you can see the PRO edition works better if a PRO uses it.