OK, maybe some of you guys who work on urban & suburban powerlines (overhead wires) might know what this is.

If anyone has seen the first movie in the Back to the Future trilogy, there is a scene where "Doc" is trying to re-connect some cable coming down from a lighting rod on the roof of a courthouse.

He's hanging from the clock hands and reaching out for a connector of some type.

Can anyone identify what kind of connector this is? It's some sort of square boxy looking thing with a female insert. He also gets the pins of the male end snagged onto his pants.

Was this a legitimate high-power connector used in the 1950s (when this is supposed to be happening) or is it just the product of some inventive props department?

Also would be nice if someone could post a nice picture if this thing really existed.