A number of war fans were use in Japanese feudal warfare, of varying size and material, for different purposes. One of the most significant, and perhaps most interesting, uses was as a signalling device. Signalling fans came in three varieties: a tasseled pom-pon, a solid iron fan, or a wood and paper one, very similar to the gunbai used today by sumo referees. The commander would raise or lower his fan and point in different ways to issue commands to the soldiers, which would then be passed on by other forms of visible and audible signalling. The art of fighting with war fans is tessenjutsu.