The 1203BB DC Motor Speed Regulator controls the speed of a DC motor by adjusting -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 supply and control the forward or reverse direction and the stop of DC motor by switch. The input 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 Before you attempting to wire the controller, make the is off. 1. wires refer to the wiring . 2. Turn on the , and adjust the potentiometer. 3. The LED indicates the 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 loads. This will damage the controller! Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.