Plastic geared motor and wheel set is an affordable and very useful product that you can use in simple applications. There is no need for an extra connection element because the motor and the wheel are tightly interlocked. Since there is a shaft output from two separate points on the motor, it can be used easily for right and left use. However, it can be used by attaching an encoder disc to the shaft side where the wheel is not attached. The encoder disk is not included in the package.