Trilon

A trilon can be made to rotate on an axle to show different text or images which may be applied to any of its three facets.

The original game board consisted of 30 motorized trilons.

Puzzle pieces were kept under high security and were attached to the trilons only as needed.

(starting with the 1984 revival, although pull-cards were used instead of trilons to show the categories until 1991).

Particularly in billboards, many long, thin trilons are placed side-by-side in the frame and periodically rotate simultaneously to cycle the billboard through three separate signs, although many have been replaced by dot-matrix signs capable of displaying a much wider range of messages.