Low angle nozzles

I have Hunter PGP rotary heads on my system. I have the regular red nozzles installed that came with the heads. I have seen low angle nozzles (gray) advertised in the literature that came with the heads. What is the advantage of using these? I can only guess that the spray will stay closer to the ground with less of an arc, but when would it be appropriate to use these?
Thanks Jim

Will allow reach under low branches.

They are used mostly in areas where heavy winds cause havoc with the spray. A lower angle will have somewhat less distance, but will also be dispersed less by the wind.