Here a puppeteer shows us the telemetry device that was used to operate Goro's upper arms. This is a somewhat lightweight casing that the puppeteer would wear. Each of his joints was matched with a potentiometer which read the movement every time the puppeteer would move his arms. He also had little controls at his fingers that he could pull and operate Goro's fingers the same way. All that information was fed to a computer which reinterpreted it and sent it back to the puppet. Basically, whatever the performer did the puppet followed.