Stimulate the kids's imagination to explore multiple ways to play with the classic electromagnetic induction principle and encourage them to operate on their own to arouse their interest in learning. When charging the generator set first open the upper cover of the boat/car and align the plug to charge. When the charging is complete remove the charging device and open the switch close the upper cover and lock itthe boat/car can start to run. Manufacturered by Ai-Fun. Shake the handle to generate electricity which can store electricity The faster you turn the handle of the wind-up prower boat/car the more power you generate has a large storage capacity lasts a long time. This is to use the saved electrical energy to drive the boat /car forward. This environmentally-friendly assembly kit does not require any batteries. The rotary handle can run the motor to charge the on-board capacitors on the generator set. After the hand-held generator handle is charged for 30 seconds or more the car travels for 2-3 minutes to test the charging effect. 2 IN 1 hand generator set car can race on land and boat can race on the water it is more playable and attractive.