VKmaker New Avoidance tracking Motor Smart Robot Car Chassis Kit Speed Encoder Battery Box 2WD Ultrasonic module with tutorial CD mechanical structure is simple and very easy to install. The package will come with tutorial CD and test code. car with four on the 5th battery compartment, convenient to the entire system power supply. At the same time equipped with a switch, easy start-stop system. Without additional very convenient, so that the whole system is highly integrated car shop with L298N driver module, four tracking module, as well as 51 control unit seamless, simple and good-looking components of the system! car comes with 20 wire tachometer yards, with photoelectric gun shop can be quickly formed a gun systems. You can speed, distance, composed of closed-loop systems.