This simple and easy-to-use DC motor speed controller has an stable performance. The output current of this motor speed controller can be adjusted from 0A to 30A, and it is simple to set. Features: Speed controller is made with high quality circuit board which ensures a longer service life. Designed with a digital display that shows the rate in percent of actual speed to maximum speed. This motor speed controller uses screw terminals for convenient and quick wiring. The positive and negative pole of controller must be connected correctly, otherwise, the item might be burnt. The input voltage of controller is better to be same as rated voltage of motor.