One quick note about the H4 adapter rings. The first time that I used them to replace the Honda original bulbs, I had all of the plastic off the bike, removed the headlight assembly and it was a piece of cake. This past fall I had a bulb fail and just needed to get it replaced. I followed one of the threads on the forum and was able to get the bulb out easily enough through the top near the steering head, however, when I went to put it back in, the adapter plate wouldn't stay attached to the bulb long enough to get it into position and I was having a hell of a time. (My adapters may not grip the bulb assembly as tight as others.) Then I remember how I keep the exhaust gaskets in my Yamaha V-Star 1100. So I put a tiny dab of high-temp RTV on the adapter ring. It held to the H4 bulb long enough to into the proper position. Clamped it it. Problem solved.