Educational Toy Kit: A scholastic tracking robot building educational toy kit for students/kids to have intellectual development, hands-on ability, and interactive skills.2 pcs C batteries are required (No battery included). Wide - Application: Robot car is widely used in school electronics learning project. Electronic-lovers and beginners can learn about basic knowledge of soldering simple circuits, photoelectric sensor, motor driving and so on from this kit. Learn While Playing: Learn puzzle and physics circuit knowledge while playing. Student can design an interesting and winding route on a flat ground to look at the robot car running. Principle: Smart tracking car is running based on the principle of the light reflectivity difference. It uses the photoresistor to tell if the smart car is on the right way or not. Easy Assembly: Every components and English instruction of the smart car kits are ready for you.It's much easier to assemble which is great for kids, beginners and hobbyist. Specification: Size: 105x87*50mm/4.13x3.13x1.97in Material: Metal+Plastic Package Includes: 1 Set Line Following Tracking Smart Car