Well, it depends on what generation of Ultra you have.
The older US's had internal threads on the body, and thus a different head design. Early on in the production of the light, two reflectors were made for it: A shiny stipled and a smoothish one that had very small, almost dull stipling. I think there may have been a third reflector with a half and half pattern, but I'm not too sure.
The latest generation Ultras have external threads on the body, and come with the shiny, half smooth/half stipled head.
If you have an older US, you may have received the most current version of head available for it, but not necessarily the latest head unit for the latest generation US.
--dan