That is one of the several attachments used on "lay op sticks" used in telephone work on outside plant, wires, trees and so on. I had and used one for many years doing telephone line work and telephone installations work We had tree trimmers operated by rope, tree saw and several other attachment to make our work easier and faster by doing some of it from the ground The sticks where right at 60 inches long, male and female ends so you could use one, two, three or four by assembling them hook together to reach up to 30 ft. or so.
Ours where all galvanized, no paint. That is the first one I've seen painted
I can't remember the proper name of that tool now, it has been more than 35 yrs since using one