Hands are the second brain outside of the head.

Ten percent of the world's population is left-handed and ambidexters are just 0.1 percent.
But why are there so many ambidexters among those known as geniuses?
The movement of the hands, especially the fingers, is directly related to brain activity.
Hands and the brain are as closely related as the movement of the hands can account for 60% of the brain motor nerve.
Tongkeunai products are composed of ten finger pens and drawing books for beginners, intermediates, and the advanced.
It is a learning material that develops the right brain and left brain of children harmoniously through drawing with finger pens.