The 1803BK DC motor speed controller controls the speed of a DC motor by adjusting the pulse width modulation (PWM). The input power range is DC 1.8-15V. Use a resettable 2A fuse to protect the controller. Potentiometer with switch function. Operating instructions: before attempting to connect the controller, make sure that the power is off. WARNING: TO CHANGE THE ENGINE DIRECTION, EXCHANGE POSITIVE AND NEGATIVE ENGINE WIRES. Connect the cables see the "wiring diagram" (picture NO.5). Turn on the power and adjust the potentiometer. The LED indicates the ignition and engine speed. Input supply voltage: 1.8V-15VDC; The maximum output power: 30W The maximum continuous output current: 2A Adjustable working cycle: 0% -100% Material: Plastic Color: green Article size: 1.3 x 1.3 x 0.6 inches; Net weight: 0.5 ounces Package content: 1 x DC motor speed controller Only the contents of the previous package, other products are not included. Note: Light shots and different screen can make the color of the image element a little different from the real object. The allowed measurement error is +/- 1-3 cm.