Feature:1. EASY INSTALLATION: Smart robot car come with simple mechanical structure, very convenient installation2. A VARIETY OF SYSTEMS: The car comes with 20 lines of tachometer code, with photoelectric gun shop can quickly form a gun system. Can be composed of speed, distance, closed loop system3. POWER SUPPLY AND SWITCH: Smart car is equipped with 4 battery compartments to facilitate the power supply of the whole system. At the same time with a switch, easy to start and stop the system4. GOOD INTEGRATION: No need for additional tools, very convenient, make the whole system highly integrated5. RELIABLE PCB: Adopt excellent PCB materials, with reliability and miniaturization, good maintenance and interchangeabilitySpecification:Item Type: Smart Robot Car Chassis KitMaterial: PCBPower Supply: 4 x AA battery(not included).Package List:1 x Car Chassis2 x Wheel2 x Motor1 x R3 Motherboard1 x V5.0 Expansion Module1 x L298N Driver1 x SG90 Module1 x SR04 Ultrasonic Module1 x USB Cable1 x User Manual1 x Battery Case1 x Caster4 x Bracket Fittings1 x Module with Line Row4 x Connecting Wires1 x No. 1 Screw Pack(4 x long screws, 4 x medium flat screws, 5 x medium tip screws, 7 x short screws, 6 x nuts)1 x No. 2 Screw Pack (3 x accessory holder, 2 x medium screws, 1 x short screws)1 x No. 3 Screw Pack (4 x long fitting, 2 x round fitting, 1 x switch, 4 x long screws, 10 x short screws, 6 x nuts, 4 x bolts)