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.