The 12 volt led dimmer switch is knob-operated control. You could adjust the brightness or turn on/off the strip lights or LED rope light via rotating the knob. dimming: 0-100% dimming range, no flickering no humming. Widely used for single color 3528/ 5050/ 5630/ 5730/ 3014 light, LED rope or ribbon lights. The cable lenght is 5.3 inches for each side and the body size: 2.56 x 1.26 x 1.34 inch. The light dimmer comes with a standard DC 5.5 x 2.1mm female/ 3.5 x 1.35mm male connector, easy to use and simple wiring. Notes: DO NOT overload use. The Max. output current is 2A and the Max. output power is 60W. The supply voltage of the light dimmer is DC12V~24V. color:Black :plastic Package Contents: 3 x dimmer switch Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.