[Chrakaknox]

I have been researching a lot of wheels lately and found O.Z. Ultraleggera's that struck my fancy. However, I've never had wheels that needed centering rings. How good/bad is it that they need them and can it cause any future issues? Otherwise, the wheels are really light and they come in black, which is what I am looking for.... Anyone have any experience with these wheels and/or anything else that needed centering rings??