100% Brand New.Intelligent car chassis Tracing car Robot car chassis with code diskIdeal for DIYMechanical structure is simple， it is easy to install.This car is the tachometer encoderWith a 4 AA battery box and power switch. (Batteries not included.)Can be used for distance measurement， velocity.Can use with other devices to realize function of tracing， obstacle avoidance， distance testing， speed testing， wireless remote control.Size: approx. 20 x 14cm(L x W); Wheel Size:6.5cm (Dia.) x 2.7cm (H)Note: motor power supply is 3V~6V. All the parameter above is tested without load.Package Content:1 x Car Chassis2 x Gear Motor2 x Car Tire2 x Speed Encoder2 x Fastener1 x Universal Wheel1 x ScrewdriverAll Necessary Screw And Nut Pls feel free to contact us!