The sails on top turn a crank, which cranks a pump, and the pump compresses air into soda bottles. From there, the compressed air is used to move pneumatic actuators which are also made from PVC, and the actuators operate the legs. Pretty neat shit, I wish he'd put bigger bottles on this thing though. Why not 5 Gal water cooler bottles? It could store a lot more air, and walk a lot longer. Higher pressures would likely make it move faster and smoother to...