HID H4HI/LO Slide shape prevents flickering and other voltage deficiency when installed It stabilizes the voltage to the ballast, does not burden on the ballast, and prevents problems such as ballast failure, and increases its life. Even though the wiring method is only used with coupler on, there is no problem with light up, ballasts and batteries can be a burden on it. It is recommended that you use it together to reduce the burden and use it for a long time. We recommend that you check the images of the wiring diagram on your PC.