Gunbai

A or  is a non-folding fan, usually made of wood. It was used in ancient Japan by samurai officers to communicate with their troops. Nowadays, it is used by referees of professional sumō matches.

Madara Uchiha has been seen wielding a large gunbai, about half his height and about his width, with the pole being twice that length. It had a chain attached to the handle that appears to have been connected to him or his kama.

Also See

 * Japanese war fan