These LEDs are accessory lights designed to be connected to your existing rear lighting system. The bulbs are 12-volt, 19-LED, 1157-style dual-intensity for the red and amber LEDs and 1156-style single intensity for the white LEDs. The lighted hole caps provide additional lighting at the rear of your truck. Keep in mind that they're not intended to replace your existing taillight/brake light system; they're just an added way to improve both looks and safety. And though it's only common sense I feel obligated to mention that the red LED are for brake and taillights, the amber for turn signals, and white for backup lights only.