There were a total of three "Voltrons": Voltron I of the Near Universe was the "Vehicle Force", and the "Lion Force" of the Far Universe was Voltron III. Voltron II, from the Middle Universe, featured three humanoid robots that combined into one multi-armed fighter; this version was never shown in the US (though toys based on this show were released). See more
In order to activate the Lions, each team member had to insert a special key. In many instances when Keith is starting the Voltron forming sequence, his key can still be seen on his tunic, but then is also seen on the panel of his lion, and then moves in the same way - left to right - as it already did when first being used to activate the Black Lion. See more
From days of long ago, from uncharted regions of the universe, comes a legend; the legend of Voltron, Defender of the Universe, a mighty robot, loved by good, feared by evil. As Voltron's legend grew, peace settled across the galaxy. On Planet Earth, a Galaxy Alliance was formed. Together with the good planets of the solar system, they maintained peace throughout the universe, until a new horrible menace threatened the galaxy. Voltron was needed once more. This is the story of the ...