This environmentally and kid-friendly vehicle reflects the new, cleaner ways we think about automobile use and demonstrates first-hand a more effective use of our natural resources. Now teaching "green" concepts is child's play! As saltwater reacts with the magnesium metal sheet (3 sheets included) in the fuel cell module, the car can operate for about 5-7 hours continuously. If you want to park the vehicle, simply take out the fuel cell module, rinse with tap water, and dry. All the materials used in this kit are environmentally safe and clean, with no toxins or disposal concerns. It will not produce heat, so it is completely safe.