100% Brand New. Size: 22 x 12xm(L x W); Wheel Size: 6.5cm (Dia.) x 2.7cm (H) Mechanical structure is simple, it is easy to install. This car is the tachometer encoder. With a 4 AA battery box. (Batteries not included.) Can be used for distance measurement, velocity. Can use with other devices to function as: tracing bot, obstacle avoidance, distance testing, speed testing, wireless remote control. Note: motor power supply is 3V~6V. All the parameter above is tested without load. DC Gear Motor No load speed (6V): 200RPM 10% No load current (6V): 200mA No load speed (3V): 90RPM 10% No load current (3V): 150mA Voltage: 3-6 V Reduction ratio is Voltage: DC 6V Current: 120MA Reduction rate: 48:1 RPM (With tire): 240 Tire Diameter: 66mm Car Speed(M/minute): 48 Motor Weight (g): 50 Motor Size: 70mm*22mm*18mm Noise: 65dB Tire Size Tire Size Center hole: Long 5.3MM, 3.5MM wide Diameter: 66MM Width: 26MM DC 6V 2-wheel Robot Smart Car Chassis Kits car with Speed Encoder for Arduino Mechanical structure is simple, very easy to install Uses four deceleration direct current machine curve to be nimble, the directivity is good. Four actuations horsepower fullness. The chassis big and steady very easy to expand. Isi Paket: 1 x Car Chassis 2 x Gear Motor 2 x Car Tire 2 x Speed Encoder 2 x Fastener 1 x Universal Wheel 1 x Screwdriver 1 x Battery Box (Batteries not included) All Necessary Screw And Nut