Features:

This car is the tachometer encoder
With a 4 AA battery box(The battery is not include)
Can be used for distance measurement, velocity
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

Specifications:

Size: 20x14cm / 7.9''x5.5''
Wheel size: 6.5×2.5cm / 2.6''x1''
Gear Motor reduction radio: 1:48

Package Include:

1 X Car Chassis
2 X Gear Motor(1:48)
2 X Car Tire
2 X Speed Encoder
2 X Fastener
1 X Universal Wheel
1 X Screwdriver
1 X Battery Box (battery is NOT included)
All Necessary Screw And Nut