Those are the 90H type reflectors, also known as halo beams because of their design, and they reflected light in both directions, providing double the usual 80-100 FPM flashes and giving the impression of a faster spinning rotator. The 80H type reflectors were an enclosed megaphone shape and only projected the light signal in one direction.
I ran across a box of a dozen brand new 90H rotator reflectors in the unopened factory packages a few years ago on eBay for a really good price. It was really nice to see and an even nicer treat to hold such hard to find vintage items in NOS condition. I no longer have them, as I sold a few individually and a charter member of the original elightbars board got the remainder of them.
So I just got one. Saved it from the brink of the dump. All I had to do was pay for shipping. It has the same rotators, and I'm seeing people say they're rare... so I guess I should really work on cleaning it up then huh?