Someone asks, What is it?

I surmise this was found at Freddy Roentgen’s yard sale, selling his grandfather’s dusty lab equipment. It’s an x-ray tube — boil off electrons, accelerate them and have them slam into the copper target, where they emit bremsstrahlung and also ionize the target, which will give some x-rays during the recombination if it involves inner-shell electrons. It’s unshielded, so it’s probably pretty old and/or taken out of a shielded device. I’d imagine a newer device to be more compact and with more recognizable connectors.