If you can get a Euro Plug and wire set, this will give you a direct connection to the pattern on the back of the Hella fixture. The us adaptor will only fit on the H4 bulb itself, but not on the Euro Weatherseal Plug. Once you see the Euro Lights, you will see what I mean. What I did was keep the Weatherseal Plug adaptor on the back of the H4 and drilled out the epoxy and fitted another wire plug. After I fitted the plug, I used WURTH epoxy to make it tight. I now can use both filaments of the H4 bulb for US highbeam wiring. I also have the city lights and proper ground. I know this is vague, but once you see the lights, it will hit ya!