Our car floor there are two, a transparent and a black. Buyers photographed, please leave a message to which color. If there is no message, random delivery Thank you! Our car chassis has the following advantages: A simple mechanical structure, very convenient to install. 2 by four deceleration DC motor turning flexible, good direction. The four-drive horsepower chronological. The Chassis large stability is very easy to extend 3 car comes velocimetry code disc with OUR guns photoelectric quickly formed a tachometer system. Velocimetry, ranging form a closed-loop system. 4 car equipped shop L293D four motor drive module, four tracking module, as well as the 51 seamless connection of the control unit, left red obstacle avoidance expansion hole, the composition of the system is simple and nice!