Listed below are the various devices found in a normal 88-note player piano. The various highlighted terms are linked to definitions. Generally speaking, all bellows are made the same way. One continuous piece of cloth is wrapped all the way around the perimeter of the bellow, and the ends of the cloth overlap. The amount of overlap varies depending on the size of the bellow.
All bellows open a certain maximum number of inches.
The amount that the bellow opens is called the 'span'. Typically, the heavy weight cloth is only used for the Exhausters and the Reservoirs . The average reservoir is usually slightly smaller than the exhauster if there are two reservoirs. If there is only one reservoir, it is always larger than the exhauster. Usually, there is a minimum of a three-inch overlap for both the exhauster and reservoir bellows.