So you will have a ball that will provide you with all different sizes of Allen Wrenches. If you need a certain size you will be able to find it in the ball and detach it from the ball. The ball will be the provider, and that's how the astronauts will carry it around with them. They will have a ball in there hand. So say that you're working on screwing something inside the shuttle. You will get the ball, detach whatever size you need. Then once you finish using that size, you can attach it back to the ball and carry around once again.