Specifications
XL: Weight: 505g / a, 18.5cm * 15.5cm * 19cm, ball diameter: 2.25cm
Large: Weight: 420g / a, 18cm * 15cm * 18cm, ball diameter: 2cm
Medium: Weight: 230g / a, 13.5cm * 11.5cm * 14cm, ball diameter: 1.5cm
Trumpet: Weight: 95g / a, 9cm * 7.5cm * 9.5cm, ball diameter: 1cm
Physics of conservation of momentum, I believe high school, are familiar.
Material: stainless steel ball ball, brackets and base for the plastic
