In this schematic the "Damper" is used most often.
A sample from the products for the Accessory(single Seat Cover) include: Cover Seat,ebony, Damper,cushion, Collar,6.8x10(16)x6.6, Washer,6x20x1.6.
The Accessory(single Seat Cover) assembly is constructed from several parts from which the Cover Seat,ebony is the most expensive.