A fuel cell produces bubbles of gas from water. This gas can be used to power a model car. Energy from 2 AA batteries is used to break apart water molecules into hydrogen and oxygen. When the hydrogen and oxygen are allowed to reform water molecules within a fuel cell, electricity is produced. Easy to use, this car demonstrates hydrogen as an alternative energy source for automobiles. (2 AA batteries and one liter of distilled water not included.) Age 10+Battery-Operated Toy - Do not mix old and new batteries. Do not mix alkaline, standard (carbon-zinc), or rechargeable (nickel-cadmium) batteries.