This amazing vehicle is powered by air! Young builders will have fun and learn with this STEM activity by building their Air Screamer. With 100 working parts and detailed instructions, kids will be able to take pride in their work. Because this great vehicle runs off of compressed air, they will have endless hours of fun without having to stop and change batteries. Safety valves are in place so that when then tank reaches optimum pressure the excess air is released. Elenco Teach products are based on STEM activities (Science, Technology, Engineering, Math) to teach and encourage kids in their development, all while having fun! All Teach Tech Green-Energy robots are powered by either water, wind, or sun, so there are no batteries required.