Put this mini robot together, then add salty water to the power compartment and off it goes No batteries required it's amazing This set of salt water includes toys powered by salt water.Assemble the robot into three different types through the child's own hands, so that the child can understand the power supply process of the robot and learn a cheap, low-carbon, green and energy-saving brine power supply mode.Adding just the right amount of salt water (1:5 concentration) will allow the robot to move. Size: Construction vehicles :13 x 4 x 6 cm Wind turbines :7 x 6 x 13 cm Robot :6 x 7 x 7 cm 0.260 Brine is synthesized to generate power, which will entertain and enthrall a kid 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 a car, a robot or a windmill, all of which are propelled by brine Recommended for children who are 8 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 year