Synchronous belt is one of the industrial belt transmission belt, also called toothed synchronous belt. According to the material points, synchronous belt can be divided into rubber synchronous belt and polyurethane synchronous belt. Rubber synchronous belt is rubber as main material, glass fiber, kevlar or other materials, industrial cord for strong core, vulcanization and synchronous belt; Polyurethane synchronous belt is a new type of polyurethane as the main raw material, steel wire or kevlar strings or other industrial cord for strong core, thermoplastic finalize the design of synchronous belt. According to the tooth type classification, synchronous belt can be divided into trapezoidal tooth ( Also called square tooth) Synchronous belt and arc-gear synchronous belt. Arc-gear synchronous belt is divided into HTD arc-gear synchronous belt, STD arc-gear synchronous belt, RPP arc-gear synchronous belt. Each type below and all kinds of different synchronous belt.