On Mon, 1 Jun 2020 03:42:38 +1000, Jake56 wrote:

Donno and wondered myself. They are a few about, possibly on poles
near fuses/air switches/auto reclosers. I wonder if they are retro
reflectors to help linesmen not familiar with the distribution(*)
locate the above key points?

Shouldn't be hard to prove/disprove that by checking if they are
only on the same pole as a switch like that one obviously is.

That one isn't on a pole with a switch, fuses or auto recloser. The
ones I've seen have been on poles near such things.

--
Cheers
Dave.