A feather duster is an implement used for cleaning. It consists typically of a wooden-dowel handle and feathers from either the male or female ostrich bird that are wound onto the handle by a wrapped wire. Dusters vary in size but are most often between 14 to 32 inches (36 to 81 cm) in total length. Some dusters have a retractable casing instead of a dowel handle. These dusters are typically used by rack-jobbers and truck drivers who need to dust store shelves, and like to retract the feathers into the handle to avoid damage. (source)