This is the DC Gear Motor With Encoder and wheel already installed. This DC Gear Motor has builtin an optical quadrature type rotary encoder. The quadrature encoders provide two pulses which are out of phase, for sensing the direction of the shaft rotation. Hence, DC Geared Motor with Encoder features both advantages of position sensing as well as direction sensing of the rotating shaft. This application flexibility of the encoders will allow you to control the speed of the base motor very precisely.
You will get 1 motor at a given price.
You need to order a minimum of 2pcs because you need 1x right side motor and 1x left side motor.