Pulley drive systems consist of two or more pulleys that connect with a belt to transmit mechanical power across greater distances than systems that use gears. Pulleys (sheaves) are available in different types: V-belt, timing, round, or flat. Pulleys must match the belts that connect them (timing pulleys with trapezoidal grooves require a belt with trapezoidal teeth) and engage either on the sides of the pulley flange (classical V-belts, narrow V-belts, or round belts), on the flat outer diameter of the pulley (flat belts), or in pulley grooves that match belt teeth (timing belts, synchronous belts, or curvilinear belts). Pulleys are made of various materials, including cast iron, steel, aluminum, polycarbonate resin thermoplastic, and nylon, and they can meet a broad range of requirements, including increased torque, resistance to wear, and light weight. Pulleys are used in drive designs in the automotive, appliance, agriculture, textile, printing, mining, and office equipment industries.

Boston Gear manufactures gears, gear drives, bearings, valves, shaft collars, couplings, and other power and fluid transmission components. The company, founded in 1877, is headquartered in Charlotte, NC, and meets International Organization for Standardization (ISO) standard 9001:2008 standard.