The zorbonaut,the person enjoying thrill of zorbing,climbs into the inside ball. There is more than 2 ft.of air between the zorbonaut and the ground to protect the person from the effect of the ball bouncing along now the zorb has been fully tested to make sure it is completely safe, which wasn't what happened originally. I broke my arm in the prototype, but we have done our best to prevent injury since then,say Andrew