Poš (gender unknown)
original: Poš (Пош)
air reservoir: flexible (usually of animal skin), ready for the insertion of stocks
Among the Mari people the general term for any type of bellows, such as those used by a blacksmith, and even that of the accordion (гармо•нь пош [Garmo•n' poš]), it is, according to the internet source, also used for the bag of the Šüvyr.