
In 1969 LEGO released the 12 volt train sets as part of the Blue Era which was named because of the rail color. These 12V train sets used additional conductor rails mounted between the standard 4.5V rails and 12V motors contained in the same housings as the 4.5V motors, but with additional metal contacts attached to the bottom of the housings.
12V consists of 17 sets that ran from 1969 to 1970. As of today,
722-2 12V Electric Train with 2 Wagons is the most valuable 12V set with an estimated new/factory sealed value of $1,154.
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