Finally! After it does not seem possible at Futsal balls is specify the sizes right, I've been using the Cawila Sala 6100 the right ball for the GSM (Bambini) and F-youth found: size 0! At just 270 grams and a circumference of 51 cm it is suitable for the little ones and can be played for example at Hamburger SchulenburgCup. From Wertingkeit he also makes a very good impression.