A Gigaball is very similar to a Zorb ball but smaller. A Zorb Ball is a large spherical ball made out of flexible plastic, it consists of two layers (the outer layer is used as a shock absorber and in between the two layers is just air). The practice of Zorbing is done using Zorb Balls. You normally enter the Zorb ball through a hole in the side, you then sit in the ball and roll down a slope in it.