Description Do you wanna experience fantastic electronics soldering? Are your kids interested in DIY electronics projects? Wanna spark and encourage child's talents and passions and keep electronics learning interesting and fun? This fun tracking smart car kit born for it. Features - Color:As Shown. - Material:Plastic, Metal, Photoresistor.- Size:11.00X8.00X2.00cm/4.32X3.14X0.79inch.- Battery: 2AA batteries (not included).-Note: The color of the circuit board is random.- Smart robot car is the most widely used in school for helping students to learn about the soldering project knowledge of mechanical structure, electronic basis skills, the principle of sensor, automatic control, soldering skill and so on.- It's much easier to assemble which is great for kids, beginners and hobbyist.- As the light reflectivity is different when the light is emitting on the white and black items. It uses the photoresistor to tell if the smart car is on the right way or not.- Smart tracking car can discriminate the direction automatically that it can run freely along the black tracking line.- You will spend quality time together and enjoy the pleasure of DIY electronics soldering. Packing list: 1 set x smart car DIY kit