1803BK DC Motor Speed Regulator controls the speed of a DC motor by adjusting Pulse-Width-Modulated (PWM). The input power range is DC 1.8-15V . Use a 2A resettable fuse to protect the controller. Potentiometer with switch function. Operating instruction: you attempting to wire the controller, make power is off. WARNING: TO CHANGE MOTOR DIRECTION, INTERCHANGE THE POSITIVE AND NEGATIVE WIRES OF MOTOR. Connect wires refer to the "wiring " (NO.5 picture). Turn on the power, and adjust the potentiometer. The LED indicates the power up and the speed of motor. Input supply voltage: 1.8V-15VDC; The maximum output power: 30W The maximum continuous output current: 2A Duty adjustable: 0%-100% Material: Plastic Colour: Green Item size: 1.3 x 1.3 x 0.6 inches; Net Weight: 0.5 ounces Package Contents: 1 x DC Motor Speed 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.