I ordered this for my shark the birthday of my son. I waited a week to receive it. But I had taken the lead and it arrived a few days before the party. The worry is that the manual was in English. I went on you tube where there is a mounting video (in English also) seeing my gestures. I managed assembly. The ball is much bigger than I imagined. Finally my son was delighted but this was short lived as the ball shark collapsed on his legos and it pierced. A drama ... So the life was short. Given the fragility I hesitate to reinvest. It is logical that if the envelope is solid, it will be too heavy and could not fly ....