Gikfun 2WD Smart Robot Car Chassis Kit With Speed encoder Battery Box 2 Motor EK1343 2WD Smart Robot Car Chassis Kit/Speed encoder Battery Box 2 motor 1:48 Mechanical structure is simple, it is easy to install Can use with other devices to realize function of tracing, obstacle avoidance, distance testing, speed testing, wireless remote control The car Chassis is transparent, you need to tear out protective paper With a 4 AA battery box and power switch. (Batteries not included.)