2X(Dimmer Luce Barra LED, Dimmer DC 12V-24V 6A, Adatto per Luce Barra LED,5486

Just turn the knob to adjust the brightness or turn on/off the light, turn the knob to the right, the light gradually brighten, and turn the knob to the left, the light gradually dim. Be sure to keep it within its specifications.

eBay