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 large gunbai with the same features. Both Madara's brown gunbai and Tobi's purple one are wide fans with tomoe on them and have long handles with bandages wrapped around the base. Both also have long chains attached to them with Madara's being attached to the handle that appears to have been connected to his kama,   whereas Tobi's chain appears to enter his sleeve.

Tobi wields his gunbai predominantly like a flail using the chain attached to guide the fan which he can use as a shield because of its durability, and was able to block a Rasengan from Naruto Uzumaki while in his Nine-Tails Chakra Mode without receiving any noticeable damage.

Trivia

 * In the anime cut-scene of Naruto Shippūden: Ultimate Ninja Storm Generations, Madara is seen using his gunbai to create powerful gusts of wind, capable of blocking projectiles and blowing enemies away, as well as a melee weapon in combination with his kama.