The grip of the ball is excellent. I ordered 5 pieces for our E-youth. Two of them lose the air faster than you can see. The others are no longer playable after 1 week without inflating. I did that significantly better experiences with balls of Kempa. The one must "never" pump up partly. Perhaps every 6-8 weeks time. The reviewed here Hummel balls have as the reviews here on Amazon almost all seem to show this problem. This is in my view an unacceptable product defect over the entire range. There should be 0 stars. But one must take one yes.
EDIT after one year: The balls were repeatedly exchanged last months ago about 5. Currently all the balls in this series are already after only 2-3 days after the inflation is no longer playable. Other balls of Kempa, Erima, adidas, who do not have to be treated identically, and claimed this problem. I will replace the 5 balls now by 5 other from another manufacturer. Incredibly bad items. That there was Hummel sometimes even better.
