The 1203BB DC Motor Speed Regulator controls the speed of a DC motor by adjusting Pulse-Width-Modulated (PWM). It provides a continuous current of 3A to your DC motor or other DC load. Besides, the circuit also includes a 3A fuse, with reverse connection of power supply and control the forward or reverse direction and the stop of DC motor by switch. The input power range is DC6-28V. Control the forward or reverse direction and the stop of DC motor by switch. Potentiometer with switch function.The switch cable length 15cm. Operating instruction you attempting to wire the controller, make that the power is off. 1. Connect wires refer to the wiring . 2. Turn on the power, and adjust the potentiometer. 3. The LED indicates the power up and the speed of motor. Colour:black Material:ABS Size:5 x 3.2 x 1.5cm Package Contents: 1 * Motor Speed Controller Warning: Do not reverse positive and negative power loads. This will damage the controller! Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.