An assembly is set of manufactured parts or components that work together in unison as one mechanism or device. A belt is a loop of flexible material used to link two or more rotating shafts mechanically, most often parallel. Belts may be used as a source of motion, to transmit power efficiently or to track relative movement. Belts are looped over pulleys and may have a twist between the pulleys, and the shafts need not be parallel. A shaft is a rotating machine element, usually circular in cross section, which is used to transmit power from one part to another, or from a machine which produces power to a machine which absorbs power. The various members such as pulleys and gears are mounted on it. Features. 12 Wirebelt Assembly Drive Shaft. Made with high quality materialSpecifications. Length 5 in / 12.70 cm. Width 24.4 in / 61.98 cm. Height 3.7 in / 9.40 cm. Size 12 in.