This mock-up of the U.S.S. Enterprise interior (bridge and transporter room) was a "giant, 24" long command center," "with captain's chair, console, two stools" plus six interchangeable "viewscreen scenes."
The set comfortably housed all the Mego Star Trek figures of the era, and, while not very show accurate in terms of design, was nonetheless a great home base for any Starfleet crew.
I remember lots of good times playing with this particular toy as a boy. I still have my original playset, which also features a handle and the capacity to fold up for mobile play. My old one is all ripped up, however, so back in 2011 I purchased this "repro" of the playset from Diamond Select. All my photos here are of that re-do of the classic toy.
Below, you can check out a 1975 commercial for the Mego U.S.S. Enterprise action playset, featuring the transporter and other features in all their glory...