Timing belt is a belt that connects the camshaft and the crankshaft in a vehicle engine (as in an automobile) and coordinates the opening and closing of the engine's valves. According to material, there are polyurethane and rubber timing belt, we mainly major in polyurethane timing belt. The PU timig belt has steel core and Kevlar core, the belt we has open ended, endless and flex. The belt surface can add green fabric (PAZ), guide, red rubber and silicone.