The originals were called XPCNs (for Xeri Pressure Compensating Nozzles) and the flow was stated in gph... for instance:
In the "first" position @ 40 psi the H at 3.0 ft radius used 13.7 GPH and a precip. rate of 1.22 in/hr.
Yet at the "second" position @ 40 psi the H at 4.0 ft radius used the same GPH, but a precip. rate of .54 in/hr.
Both of these as laid out with no overlap.
I didn't really look at the post card yet to see whether these are the same thing or something different.
Landscaper. Irrigator. Illuminator. Music lover. Coffee drinker.