Product Details 

• Smart car chassis tracing car Robot car chassis with code disk
• Ideal for DIY
• 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 realize the function of tracing, obstacle avoidance, distance testing, speed testing, wireless remote control
• Size: 20 x 14cm (L x W)
• Wheel size: 6.5 x 2.7cm (Dia. x H)