VHS-style video tapes back in 1971?
When Bill McKay (Robert Redford) and his political team are viewing some of his recent campaign footage on tv monitors, the guy in charge of video shows him a plastic container. This container apparently contains footage of McKay's recent health care facility visit. He goes into a back room and installs the contents of the container and they watch the health care facility foogage (which turns out to be problematic due to the lack of rapport McKay has with the people whom he's trying to talk to).
What kind of video tape did they use for this scene? Since this movie was shot back in 1971, prior to more recent VHS, what kind of technology was available in order to play video tapes on television monitors?