Run with either solar energy or AA electricity, so it can run indoor and outdoor. 100% DIY toy which is good to develop the Practical ability It is solar energy toy which make children loving science and have good habit. It is popularly used for solar car racing in school. The structure is simple and easy-assembled. You can finish assembling within 5 minutes. Size is 20*8*7.5 cm which is not too small and not too big. The power of solar panel is 0.3Watt to make sure generating enough power to run fast. Use strong motor. The direction of car can adjusted with 45-135 degree. We have got the patent for this toy. It is recommended primary and secondary school science education equipment and is specially designed for school new energy education,. For sure, it is a very good gift for children,too.