This is a soccer ball specifically designed for improving technique, sold by E3 Shop. It has been used about 10 times and is a little dirty (I've wiped it down and inflated it). It looks like a regular ball, but due to its uniquely developed balance, it can bounce normally, or the spin and bounce can change irregularly depending on where you hit the ball. The feel of kicking the ball, its rebound, and its weight are the same as a regular size 4 ball, but by making it smaller, the size of a size 2 ball, using a special manufacturing process, it increases the difficulty of practice and provides a lot of stimulation to the brain and nervous system. I think it will help improve body control and ball control. As mentioned above, it is a little dirty, so please refrain from purchasing if you are concerned. No claims and no returns, please.