The rebound ball is simple design at its finest (and aren't simple toys often the best?). It consists of a soft rubber ball attached to a Velcro wrist strap by four or five feet of elastic band. Once the strap is securely fastened, throwing the ball with sufficient force will result in it snapping back towards you, either to be caught or dodged. Despite its uncomplicated function, even as an adult I find it fun to play with - especially indoors. So long as there isn't anything breakable nearby.