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 and Tobi have been seen wielding a large gunbai, about 3/4 of their height and almost of their width, with the pole being twice that length. Madara's had a chain attached to the handle that appears to have been connected to his kama,   whereas Tobi's chain appears to enter his sleeve.