Part numbers equipped with relays will bypass the power draw from the headlight switch by pulling power directly from the car's battery, this will increase your light out-put on your headlights and you can still use your factory headlight or fog light switch! These harnesses do not include any extra wiring for turn signals or parking lights. Parts equipped with relays are not intended to work with vehicles equipped with DRLs. Available for 9004, 9007, 9006, 9012, H13, 9008 and H4.