25mm Encoder DC Motor Pack includes two encoder motors, one encoder motor driver and two cables. In contrast to the DC motor, a photoelectric encoder is added into the encoder motor for detecting speed which is fed back to the signal input terminal for PID control to implement servo control for the motor.
Features:
? Control the speed and displacement for the motor precisely;
? Users can customize their own PID parameter by self-contained software;
? It provides overload protection.
Parts List: 
1 x Me Encoder Motor Driver
2 x Optical Encoder Motor-25 9V/185RPM
2 x Encoder Motor Wire