Little Treasures Rubber Band Powered Propeller Engines Educational Kit Powered by rubber bands are used to create tension and power the vehicles. Learn about power and propulsion, and rates of speed and different options when there are different vehicles built! This kit comes with the ability to build two different vehicles, one at a time! Recommended for children who are eight years of age or older. Made with safe and non-toxic plastic materials  contains small parts keep out of reach of children under the age of 3 years.