This is the Cooper Lighting Caretaker LED Roadway Luminaire. They are compatible with open bottom refractors. My guess is the lineman who installed this put the open bottom refractor from the old NEMA head on this luminaire.
I bet the wasps will love these. The LEDs don't put out enough heat to keep them out. Those buckets provide a nice enclosure from the wind and rain. Any NEMA I've seen that doesn't work is FILLED with wasp nests.