Features: 1203B DC Motor Speed Regulator controls the speed of a DC motor by adjusting Pulse-Width-Modulated (PWM). The input power range is DC 6V-28V .Duty Cycle adjustable range is 0%-100%.Operating instruction: Before you attempting to wire the controller, make sure power is off.WARNING: DO NOT REVERSE POSTIVE AND NEGATIVE POWER LOADS.THIS WILL DAMAGE THE CONTROLLER. TO CHANGE MOTOR DIRECTION, INTERCHANGE THE POSITIVE AND NEGATIVE WIRES OF MOTOR.Color: picture colorMaterial: PC + metalSize: 5*3.2*1.5cmPackage Contents: 1 x DC Motor Speed ControllerOnly 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.